Ustilaginales Black and White Stock Photos & Images

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. V] LABOULBENIALES 171 LABOULBENIALES The group Laboulbeniales includes some six hundred species arranged in over fifty genera. All are minute external parasites on insects, chiefly on members of the Coleoptera. They appear to do but little injury to the host, inducing at most a slight irritation but never causing death; indeed their own existence depends on that of the insect to which they are attached since, unlike many other fungi, their life ends with that of their host. The Laboulbeniales are all of fairly simple structure (fig. 130) Stock Photo

RMRDX151–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. V] LABOULBENIALES 171 LABOULBENIALES The group Laboulbeniales includes some six hundred species arranged in over fifty genera. All are minute external parasites on insects, chiefly on members of the Coleoptera. They appear to do but little injury to the host, inducing at most a slight irritation but never causing death; indeed their own existence depends on that of the insect to which they are attached since, unlike many other fungi, their life ends with that of their host. The Laboulbeniales are all of fairly simple structure (fig. 130)

. Botany for agricultural students . Botany. Fig. 348. — A Bird's Nest Fungus, Nidularia. About natural size. organic matter in the ground. Tlie sporophore is at first globose, but the gleba soon breaks out of the peridium and is elevated to some distance above ground by an elongating stalk. The spore masses arc slimy and have the odor of carrion. Certain insects which dissemi- nate the spores are attracted by the odor. Smuts (Ustilaginales). — The Smuts are parasitic Basidiomycetes. In some Smuts, the mycelium, although evident only in local areas, traverses widely through the host, while in Stock Photo

RMPG4ATE–. Botany for agricultural students . Botany. Fig. 348. — A Bird's Nest Fungus, Nidularia. About natural size. organic matter in the ground. Tlie sporophore is at first globose, but the gleba soon breaks out of the peridium and is elevated to some distance above ground by an elongating stalk. The spore masses arc slimy and have the odor of carrion. Certain insects which dissemi- nate the spores are attracted by the odor. Smuts (Ustilaginales). — The Smuts are parasitic Basidiomycetes. In some Smuts, the mycelium, although evident only in local areas, traverses widely through the host, while in

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. . Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Gwynne-Vaughan, Helen Charlotte Isabella (Fraser) Dame, 1879-. Cambridge [Eng] University Press Stock Photo

RMRDX1KT–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. . Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Gwynne-Vaughan, Helen Charlotte Isabella (Fraser) Dame, 1879-. Cambridge [Eng] University Press

. Botany for agricultural students . Botany. 392 THALLOPHYTES. Fig. 348. — A Bird's Nest Fungus, Nidularia. About natural size. organic matter in the ground. Tlie sporophore is at first globose, but the gleba soon breaks out of the peridium and is elevated to some distance above ground by an elongating stalk. The spore masses arc slimy and have the odor of carrion. Certain insects which dissemi- nate the spores are attracted by the odor. Smuts (Ustilaginales). — The Smuts are parasitic Basidiomycetes. In some Smuts, the mycelium, although evident only in local areas, traverses widely through t Stock Photo

RMPG4ATP–. Botany for agricultural students . Botany. 392 THALLOPHYTES. Fig. 348. — A Bird's Nest Fungus, Nidularia. About natural size. organic matter in the ground. Tlie sporophore is at first globose, but the gleba soon breaks out of the peridium and is elevated to some distance above ground by an elongating stalk. The spore masses arc slimy and have the odor of carrion. Certain insects which dissemi- nate the spores are attracted by the odor. Smuts (Ustilaginales). — The Smuts are parasitic Basidiomycetes. In some Smuts, the mycelium, although evident only in local areas, traverses widely through t

RMRDX1Y7–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. . Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Gwynne-Vaughan, Helen Charlotte Isabella (Fraser) Dame, 1879-. Cambridge [Eng] University Press

. Farm friends and farm foes : a text-book of agricultural science . Agricultural pests; Beneficial insects; Insect pests. CHAPTER XX The Smut Fungi The Smuts form a distinctive group of parasitic plants called by botanists Ustilaginales. The mycelium develops in the tissues of the host plant and causes serious injury to the parts infested. Spores are developed in the form of the blackish powder so characteristic of Corn Smut and Oats Smut. These primary spores germinate under favor- able conditions and often bring about the development of enormous numbers of secondary spores. Nearly every one Stock Photo

RMPG4660–. Farm friends and farm foes : a text-book of agricultural science . Agricultural pests; Beneficial insects; Insect pests. CHAPTER XX The Smut Fungi The Smuts form a distinctive group of parasitic plants called by botanists Ustilaginales. The mycelium develops in the tissues of the host plant and causes serious injury to the parts infested. Spores are developed in the form of the blackish powder so characteristic of Corn Smut and Oats Smut. These primary spores germinate under favor- able conditions and often bring about the development of enormous numbers of secondary spores. Nearly every one

RMRDX0HG–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. . Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Gwynne-Vaughan, Helen Charlotte Isabella (Fraser) Dame, 1879-. Cambridge [Eng] University Press

RMRDX1RF–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. . Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Gwynne-Vaughan, Helen Charlotte Isabella (Fraser) Dame, 1879-. Cambridge [Eng] University Press

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. ^<#s^. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Gwynne-Vaughan, Helen Charlotte Isabella (Fraser) Dame, 1879-. Cambridge [Eng] University Press Stock Photo

RMRDTNJX–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. ^<#s^. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Gwynne-Vaughan, Helen Charlotte Isabella (Fraser) Dame, 1879-. Cambridge [Eng] University Press

. Botany, with agricultural applications. Botany. 384 THALLOPHYTES are divided into a number of orders. The most familiar orders are those represented by the Toadstools and Mushrooms (Hy- menomycetes), Puff balls (Gasteromycetes), Smuts {Ustilaginales), and Rusts (Uredinales). Toadstools and Mushrooms (Hymenomycetes). — This is the most familiar order to most people, because it includes so many forms like the Toadstools and Mushrooms, which have conspicu- ous sporophores. In addition to the Toadstools and Mushrooms, the order contains some other rather famihar kinds of Fungi. The Fungi of this Stock Photo

RMRDWD0M–. Botany, with agricultural applications. Botany. 384 THALLOPHYTES are divided into a number of orders. The most familiar orders are those represented by the Toadstools and Mushrooms (Hy- menomycetes), Puff balls (Gasteromycetes), Smuts {Ustilaginales), and Rusts (Uredinales). Toadstools and Mushrooms (Hymenomycetes). — This is the most familiar order to most people, because it includes so many forms like the Toadstools and Mushrooms, which have conspicu- ous sporophores. In addition to the Toadstools and Mushrooms, the order contains some other rather famihar kinds of Fungi. The Fungi of this

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. ^B Ervsiphales The Erysiphales are characterized by an abundant superficial mycelium, which may be white (colourless) or dark-coloured. The perithecia are spherical, ovoid or flattened, and are usually without an ostiole; the peridium is thin and membranous; the asci are arranged in a regular layer at the base of the perithecium. The group includes some 600 species, the majority of which are external parasites or epiphytes upon the leaves of higher plants. They are grouped into three families, of which the Microthyriaceae are but little k Stock Photo

RMRDTP6P–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. ^B Ervsiphales The Erysiphales are characterized by an abundant superficial mycelium, which may be white (colourless) or dark-coloured. The perithecia are spherical, ovoid or flattened, and are usually without an ostiole; the peridium is thin and membranous; the asci are arranged in a regular layer at the base of the perithecium. The group includes some 600 species, the majority of which are external parasites or epiphytes upon the leaves of higher plants. They are grouped into three families, of which the Microthyriaceae are but little k

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 124 DISCOMYCETES [CH. members of the Vaccinieae, where the sclerotia are formed on the fruits. In 5. Vaccuni the conidia are produced in chains and are separated by small cellulose disjunctors. They have a characteristic smell of almonds and are carried to the flower by insects, and probably also by wind ; they germinate to form septate hyphae which enter and fill the ovar}'. The. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these Stock Photo

RMRDTNN6–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 124 DISCOMYCETES [CH. members of the Vaccinieae, where the sclerotia are formed on the fruits. In 5. Vaccuni the conidia are produced in chains and are separated by small cellulose disjunctors. They have a characteristic smell of almonds and are carried to the flower by insects, and probably also by wind ; they germinate to form septate hyphae which enter and fill the ovar}'. The. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 78 PLECTOMYCETES [CH.. ^B Ervsiphales The Erysiphales are characterized by an abundant superficial mycelium, which may be white (colourless) or dark-coloured. The perithecia are spherical, ovoid or flattened, and are usually without an ostiole; the peridium is thin and membranous; the asci are arranged in a regular layer at the base of the perithecium. The group includes some 600 species, the majority of which are external parasites or epiphytes upon the leaves of higher plants. They are grouped into three families, of which the Microthyr Stock Photo

RMRDTP6Y–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 78 PLECTOMYCETES [CH.. ^B Ervsiphales The Erysiphales are characterized by an abundant superficial mycelium, which may be white (colourless) or dark-coloured. The perithecia are spherical, ovoid or flattened, and are usually without an ostiole; the peridium is thin and membranous; the asci are arranged in a regular layer at the base of the perithecium. The group includes some 600 species, the majority of which are external parasites or epiphytes upon the leaves of higher plants. They are grouped into three families, of which the Microthyr

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 148 PYRENOMYCETES [CH. two nuclei each. In his opinion, the second nucleus in the originally uni- nucleate cell, is derived from its multinucleate neighbour, which he terms the antheridium ; the other binucleate cells receive their nuclei from it by conjugate division, and are the beginnings of ascogenous hyphae. Though he was unable to see either the entrance of the second nucleus, or the process of conjugate division, his facts are decidedly suggestive, but they point less to normal fertilization than to the pseudapogamous association o Stock Photo

RMRDTNDD–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 148 PYRENOMYCETES [CH. two nuclei each. In his opinion, the second nucleus in the originally uni- nucleate cell, is derived from its multinucleate neighbour, which he terms the antheridium ; the other binucleate cells receive their nuclei from it by conjugate division, and are the beginnings of ascogenous hyphae. Though he was unable to see either the entrance of the second nucleus, or the process of conjugate division, his facts are decidedly suggestive, but they point less to normal fertilization than to the pseudapogamous association o

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. Fig. 130. ; triordinata Thaxter; x 135; after Thaxter. Fig. 131. Laboulbenia chaetophora young perithecium and triclio- gyne, x 360 ; after Faull.. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Gwynne-Vaughan, Helen Charlotte Isabella (Fraser) Dame, 1879-. Cambridge [Eng] University Press Stock Photo

RMRDX14P–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. Fig. 130. ; triordinata Thaxter; x 135; after Thaxter. Fig. 131. Laboulbenia chaetophora young perithecium and triclio- gyne, x 360 ; after Faull.. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Gwynne-Vaughan, Helen Charlotte Isabella (Fraser) Dame, 1879-. Cambridge [Eng] University Press

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 204 PROTOBASIDIOMYCETES [CH. But the fact that these sori are developed on the same mycelium as the spermogonia, the fact that in their "fertile cells nuclear association takes place and the fact that in the formation of the fertile cell a sterile cell is cut off, all suggest that the true homology is with the aecidium. The mycelium formed by the germination of the aecidiospore grows with renewed energy. It consists of binucleate cells giving rise to uredospores. These are borne in groups or uredosori (fig. 179) which may be surround Stock Photo

RMRDX0K4–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 204 PROTOBASIDIOMYCETES [CH. But the fact that these sori are developed on the same mycelium as the spermogonia, the fact that in their "fertile cells nuclear association takes place and the fact that in the formation of the fertile cell a sterile cell is cut off, all suggest that the true homology is with the aecidium. The mycelium formed by the germination of the aecidiospore grows with renewed energy. It consists of binucleate cells giving rise to uredospores. These are borne in groups or uredosori (fig. 179) which may be surround

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. V] HYPOCREALES 151 As development proceeds the ovate or flask-shaped perithecia are dif- ferentiated ; they always arise deep in the stroma and may remain completely or partially immersed or may become superficial as they approach maturity. Where they are more or less free the surface of the head is usually rough, whereas when they are entirely immersed it is smooth, but in some cases the free perithecia stand so close together as to produce a smooth appearance. The cytological details of development have not been studied; the perithecia Stock Photo

RMRDTNCY–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. V] HYPOCREALES 151 As development proceeds the ovate or flask-shaped perithecia are dif- ferentiated ; they always arise deep in the stroma and may remain completely or partially immersed or may become superficial as they approach maturity. Where they are more or less free the surface of the head is usually rough, whereas when they are entirely immersed it is smooth, but in some cases the free perithecia stand so close together as to produce a smooth appearance. The cytological details of development have not been studied; the perithecia

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. I40 PYRENOMYCETES [CH. The Hypocreales, Dothideales and Sphaeriales, have in conjmon more or less pyriform or flask-shaped perithecia; these are sometimes isolated and free, sometimes sunk in the tissue of the host, and sometimes embedded in a stroma or cushion of fungal tissue. The perithecium is lined by delicate filaments, some of which, the periphyses, grow along and partially close the neck, and may protrude through the ostiole, while others (paraphyses) are mingled with the asci in the venter of the fruit. The neck of the peri- thec Stock Photo

RMRDTNFG–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. I40 PYRENOMYCETES [CH. The Hypocreales, Dothideales and Sphaeriales, have in conjmon more or less pyriform or flask-shaped perithecia; these are sometimes isolated and free, sometimes sunk in the tissue of the host, and sometimes embedded in a stroma or cushion of fungal tissue. The perithecium is lined by delicate filaments, some of which, the periphyses, grow along and partially close the neck, and may protrude through the ostiole, while others (paraphyses) are mingled with the asci in the venter of the fruit. The neck of the peri- thec

RMRDX0Y9–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 186 HEMIBASIDIOMYCETES [CH. fields. As a rule the conidia are of the same oblong form as the basidio- spores, but, in the genus Tilletia and some of its allies, they may be stout or sickle-shaped, whereas the basidiospores are long and narrow. In Entyloma the brand-spores are capable of germination on the tissues of the host leaf, where they give rise to hyphae which penetrate through the stomata and form basidia from which basidiospores are produced. During their development the cells of the basidium, the basidiospores, or the conidia bu

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. V] HYPOCREALES 147 of these spermatia have failed, and no relation of any kind has been de- monstrated between them and the female organ, consequently they must be regarded as no longer functional, and their original use can be inferred only from their structure. Their small size, scanty contents, and large nucleus suggest that they are more appropriately constituted to act as fertilizing agents than as a means of vegetative propagation. The archicarp first appears as a multinucleate hypha, which becomes septate and somewhat elaborately c Stock Photo

RMRDTNDR–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. V] HYPOCREALES 147 of these spermatia have failed, and no relation of any kind has been de- monstrated between them and the female organ, consequently they must be regarded as no longer functional, and their original use can be inferred only from their structure. Their small size, scanty contents, and large nucleus suggest that they are more appropriately constituted to act as fertilizing agents than as a means of vegetative propagation. The archicarp first appears as a multinucleate hypha, which becomes septate and somewhat elaborately c

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 198 PROTOBASIDIOMYCETES [CH. (sporidium) is formed and receives the nucleus and cytoplasm of the cell from which it arose. In Coleosporiuni, Ochropsora, and Chrysospora, nuclear division and septation take place within the teleutospore wall, and the basidiospores are budded out from it, so that the teleutospore cell becomes the basidium directly; in the majority of cases, however, the structure of the teleutospore is not such as readily to allow further growth, and development takes place after the extrusion of the contents as a tubular o Stock Photo

RMRDX0RB–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 198 PROTOBASIDIOMYCETES [CH. (sporidium) is formed and receives the nucleus and cytoplasm of the cell from which it arose. In Coleosporiuni, Ochropsora, and Chrysospora, nuclear division and septation take place within the teleutospore wall, and the basidiospores are budded out from it, so that the teleutospore cell becomes the basidium directly; in the majority of cases, however, the structure of the teleutospore is not such as readily to allow further growth, and development takes place after the extrusion of the contents as a tubular o

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. or four cells, which diminish gradually in diameter and which he terms a trichogyne. In Ascobolus inimersus the mycelium consists of multinucleate cells, the archicarp is larger than that of A. Winteri and contains some twenty divisions, it is otherwise very similar. The cells contain numerous large nuclei and pores develop between them ; the ascogenous hyphae arise from a single cell. Ramlow observed nuclear fusions in the central cell of the archicarp, but referred them to bad fixation. His explanation may be adequate here, but it does Stock Photo

RMRDTXT0–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. or four cells, which diminish gradually in diameter and which he terms a trichogyne. In Ascobolus inimersus the mycelium consists of multinucleate cells, the archicarp is larger than that of A. Winteri and contains some twenty divisions, it is otherwise very similar. The cells contain numerous large nuclei and pores develop between them ; the ascogenous hyphae arise from a single cell. Ramlow observed nuclear fusions in the central cell of the archicarp, but referred them to bad fixation. His explanation may be adequate here, but it does

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. CHAPTER IV DISCOMYCETES The term Discomycetes is applied to those groups in which the fruit is more or less cup-shaped (fig. 51), with the hymenium fully exposed at maturity, and to their immediate allies. The ascocarp is surrounded by a peridium or sheath of closely interwoven hyphae which is closed at first and later is pushed apart by the paraphyses, so that at last it forms the outer. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance o Stock Photo

RMRDTP3D–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. CHAPTER IV DISCOMYCETES The term Discomycetes is applied to those groups in which the fruit is more or less cup-shaped (fig. 51), with the hymenium fully exposed at maturity, and to their immediate allies. The ascocarp is surrounded by a peridium or sheath of closely interwoven hyphae which is closed at first and later is pushed apart by the paraphyses, so that at last it forms the outer. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance o

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. IV] DISCOMYCETES 97 may, by invagination of the fertile surface, have produced the closed fruit of the truffles. The simpler Tuberales may have had a similar origin, or may have arisen direct from a pezizaceous form, such as Sepultaria, with which Genea has several points in common. It is not impossible that theRhiziita group, by the development of a sterile stalk, has also produced the Helvellaceae and it may be the Geoglossaceae as well. But the latter family, because of the characteristic method of dehis- cence of its ascus (by the eje Stock Photo

RMRDTP2N–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. IV] DISCOMYCETES 97 may, by invagination of the fertile surface, have produced the closed fruit of the truffles. The simpler Tuberales may have had a similar origin, or may have arisen direct from a pezizaceous form, such as Sepultaria, with which Genea has several points in common. It is not impossible that theRhiziita group, by the development of a sterile stalk, has also produced the Helvellaceae and it may be the Geoglossaceae as well. But the latter family, because of the characteristic method of dehis- cence of its ascus (by the eje

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. VIII] UREDINALES 209 form; in both cases it is borne in association with spermogonia on a myceHum of uninucleate cells. But the spore germinates like a teleutospore. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Gwynne-Vaughan, Helen Charlotte Isabella (Fraser) Dame, 1879-. Cambridge [Eng] University Press Stock Photo

RMRDX0H8–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. VIII] UREDINALES 209 form; in both cases it is borne in association with spermogonia on a myceHum of uninucleate cells. But the spore germinates like a teleutospore. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Gwynne-Vaughan, Helen Charlotte Isabella (Fraser) Dame, 1879-. Cambridge [Eng] University Press

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 8o PLECTOMYCETES [CH. enter the stomata, extend through the intercellular spaces and send haustoria into the neighbouring cells, and in Erysiphe (or Oidiopsis) taurica the whole mycelium during the conidial stage is located in the tissues of the host. We have thus, within the limits of the family, a transition between ecto- and endoparasitism through hemiendophytic forms, and forms which are endo- phytic under abnormal conditions. When perithecia are about to be produced and the mycelium emerges and spreads over the surface of the host le Stock Photo

RMRDTP6H–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 8o PLECTOMYCETES [CH. enter the stomata, extend through the intercellular spaces and send haustoria into the neighbouring cells, and in Erysiphe (or Oidiopsis) taurica the whole mycelium during the conidial stage is located in the tissues of the host. We have thus, within the limits of the family, a transition between ecto- and endoparasitism through hemiendophytic forms, and forms which are endo- phytic under abnormal conditions. When perithecia are about to be produced and the mycelium emerges and spreads over the surface of the host le

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 98 DISCOMYCETES [CH. should be ultimately established, the curious stalked conidium of Ascobolus carbonarius. The archicarp is of much commoner occurrence, and seems more likely to be useful as a gauge of relationship. Among Discomycetes the simplest type is undoubtedly that ol Ascodesmis or Tkelebolus; the significant details in Tkelebolus are not fully known, but in Ascodesmis we have a stout, twisted hypha, divided into three parts, the unicellular trichogyne, the unicellular coenocytic oogonium and the multicellular stalk (fig. 56). A Stock Photo

RMRDTP2H–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 98 DISCOMYCETES [CH. should be ultimately established, the curious stalked conidium of Ascobolus carbonarius. The archicarp is of much commoner occurrence, and seems more likely to be useful as a gauge of relationship. Among Discomycetes the simplest type is undoubtedly that ol Ascodesmis or Tkelebolus; the significant details in Tkelebolus are not fully known, but in Ascodesmis we have a stout, twisted hypha, divided into three parts, the unicellular trichogyne, the unicellular coenocytic oogonium and the multicellular stalk (fig. 56). A

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. "I] PLECTASCALES 59. Fig. 19. Eremascus fertilis Stoppel; stages in the formation of tlie ascus, both by fusion of two cells and parthenogenetically; after Guilliermond.. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Gwynne-Vaughan, Helen Charlotte Isabella (Fraser) Dame, 1879-. Cambridge [Eng] University Press Stock Photo

RMRDX1MC–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. "I] PLECTASCALES 59. Fig. 19. Eremascus fertilis Stoppel; stages in the formation of tlie ascus, both by fusion of two cells and parthenogenetically; after Guilliermond.. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Gwynne-Vaughan, Helen Charlotte Isabella (Fraser) Dame, 1879-. Cambridge [Eng] University Press

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. VIII] UREDINALES 215 vegetative nucleus has replaced that of the no longer functional male element. As already shown there is a strong presumption that this male element was the spermatium and the fertile cell may then be regarded as an oogonium and the young aecidium as a group or sorus of female reproductive organs. In this connection Blackman has suggested a possible origin of the sterile cell; in Phragmidium violaceum he found it to be occasionally elongated and pushed up between the cells of the epidermis so that it was covered only Stock Photo

RMRDX0ER–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. VIII] UREDINALES 215 vegetative nucleus has replaced that of the no longer functional male element. As already shown there is a strong presumption that this male element was the spermatium and the fertile cell may then be regarded as an oogonium and the young aecidium as a group or sorus of female reproductive organs. In this connection Blackman has suggested a possible origin of the sterile cell; in Phragmidium violaceum he found it to be occasionally elongated and pushed up between the cells of the epidermis so that it was covered only

. The British rust fungi (Uredinales) their biology and classification. Rust fungi. PHYLOGENY 83 From these considerations the probable phylogeny of the Uredinales may be represented as in the following schemes. Ascomycetes Basidiomycetes Uredinales. Ustilaginales Rhodophycese Pucciniacese Endophyllum. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Grove, W. B. (William Bywater), 1848-1938. Cambridge, University Press Stock Photo

RMRE3885–. The British rust fungi (Uredinales) their biology and classification. Rust fungi. PHYLOGENY 83 From these considerations the probable phylogeny of the Uredinales may be represented as in the following schemes. Ascomycetes Basidiomycetes Uredinales. Ustilaginales Rhodophycese Pucciniacese Endophyllum. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Grove, W. B. (William Bywater), 1848-1938. Cambridge, University Press

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 208 PROTOBASIDIOMYCETES [CH. the usual way. In the micro- form Puccinia transformans OHve observed that the binucleate condition was brought about by the fusion in pairs of cells to form the basal cells from which the teleutospores arose and the same has been reported by Moreau for Puccinia Buxi and Uromyces Ficariae. In Puccinia Malvacearuni Moreau occasionally found a difference in size between the fusing cells, and Werth and Ludwig observed the migration of the nucleus of the smaller cell into the larger (fig. i84«). Below the teleutos Stock Photo

RMRDX0HK–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 208 PROTOBASIDIOMYCETES [CH. the usual way. In the micro- form Puccinia transformans OHve observed that the binucleate condition was brought about by the fusion in pairs of cells to form the basal cells from which the teleutospores arose and the same has been reported by Moreau for Puccinia Buxi and Uromyces Ficariae. In Puccinia Malvacearuni Moreau occasionally found a difference in size between the fusing cells, and Werth and Ludwig observed the migration of the nucleus of the smaller cell into the larger (fig. i84«). Below the teleutos

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 84 PLECTOMYCETES [CH. de Bary, who was able to recognize an antheridium and oogonium and the formation of an ascus or asci from the latter. These and several subsequent investigations have rendered the reproductive processes in the Erysiphaceae better known than perhaps in any other group of fungi. Sphaerotheca Humuli^ occurs on a variety of common plants, on the cultivated strawberry, where it is responsible for strawberry mildew, and especially on the hop. On the latter it is widely distributed in autumn, and, if the female inflorescenc Stock Photo

RMRDTP60–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 84 PLECTOMYCETES [CH. de Bary, who was able to recognize an antheridium and oogonium and the formation of an ascus or asci from the latter. These and several subsequent investigations have rendered the reproductive processes in the Erysiphaceae better known than perhaps in any other group of fungi. Sphaerotheca Humuli^ occurs on a variety of common plants, on the cultivated strawberry, where it is responsible for strawberry mildew, and especially on the hop. On the latter it is widely distributed in autumn, and, if the female inflorescenc

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. IV] PEZIZALES "3 mitoses. This implies that the gametophytic number is four, and that the gemini are formed immediately after the fusion in the oogonium, so that in the ascogenous hyphae there are four bivalent instead of eight univalent chromosomes. In the meiotic prophase which follows the fusion in the ascus, there is a double number of gemini, since two sporophytic nuclei have united. In Humaria granulata, the antheridium has disappeared and normal fertilization is replaced by fusion of female nuclei in pairs in the oogonium.. Fi Stock Photo

RMRDTNYM–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. IV] PEZIZALES "3 mitoses. This implies that the gametophytic number is four, and that the gemini are formed immediately after the fusion in the oogonium, so that in the ascogenous hyphae there are four bivalent instead of eight univalent chromosomes. In the meiotic prophase which follows the fusion in the ascus, there is a double number of gemini, since two sporophytic nuclei have united. In Humaria granulata, the antheridium has disappeared and normal fertilization is replaced by fusion of female nuclei in pairs in the oogonium.. Fi

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. V] SPHAERIALES 169 The perithecium is initiated by the development of a coil of large, deeply-staining cells forming the archicarp. It arises amongst the vegetative filaments of the stroma, forms a couple of loops and is continued towards the surface of the stroma as a.slender multicellular trichogyne (fig. 127a). At an early stage the coiled portion becomes surrounded by a knot of small, densely-staining hyphae; later the trichogyne disappears, degeneration progressing from the base to the apex; the investing filaments grow more actively Stock Photo

RMRDX15P–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. V] SPHAERIALES 169 The perithecium is initiated by the development of a coil of large, deeply-staining cells forming the archicarp. It arises amongst the vegetative filaments of the stroma, forms a couple of loops and is continued towards the surface of the stroma as a.slender multicellular trichogyne (fig. 127a). At an early stage the coiled portion becomes surrounded by a knot of small, densely-staining hyphae; later the trichogyne disappears, degeneration progressing from the base to the apex; the investing filaments grow more actively

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. Ill] PLECTASCALES 63 succinic acid, acetic acid, and small quantities of other substances. The amount of these by-products varies during the progress of fermentation and according to external conditions. In particular, fermentation is affected by the presence or absence of free oxygen. Under conditions of plentiful aeration the yeast grows and multiplies rapidly and much of the sugar is used as food; under anaerobic conditions, on the other hand, the main part of the sugar is utilized in respiration, alcoholic fermentation is more complet Stock Photo

RMRDX1JR–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. Ill] PLECTASCALES 63 succinic acid, acetic acid, and small quantities of other substances. The amount of these by-products varies during the progress of fermentation and according to external conditions. In particular, fermentation is affected by the presence or absence of free oxygen. Under conditions of plentiful aeration the yeast grows and multiplies rapidly and much of the sugar is used as food; under anaerobic conditions, on the other hand, the main part of the sugar is utilized in respiration, alcoholic fermentation is more complet

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. n] ASCOMYCETES 49 brane which gradually closes in to produce, by further marginal growth, the ellipsoidal plasma membrane of the spore. In this way the whole body of the spore is cut out from the undifferentiated cytoplasm of the ascus by a process of free cell formation, and its membrane is formed by the fusion of the astral rays. A different account of, the development of the membrane was given by Faull in 1905. According to his investigations the spore is cut out by the gradual differentiation from the centrosome downwards of a limitin Stock Photo

RMRDX1N6–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. n] ASCOMYCETES 49 brane which gradually closes in to produce, by further marginal growth, the ellipsoidal plasma membrane of the spore. In this way the whole body of the spore is cut out from the undifferentiated cytoplasm of the ascus by a process of free cell formation, and its membrane is formed by the fusion of the astral rays. A different account of, the development of the membrane was given by Faull in 1905. According to his investigations the spore is cut out by the gradual differentiation from the centrosome downwards of a limitin

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. Fig. 82. Saccobolus violascens Boud.; archicarp; after Dangeard. Fig. 83. Thehbolus stercoreus Tde.; ascocarp with single ascus, X250; after Brefeld. The species of Rhyparobius and Thelebolus, the two genera with many- spored asci, are all minute, coprophilous forms. They are distinguished by the fact that Rhyparobius produces several large asci, and Thelebolus only one (fig. 83). In both genera the cells of the mycelium are uninucleate. In Rhyparobius {Thecotheus) Pelletieri Overton has described several. Please note that these images ar Stock Photo

RMRDTNNN–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. Fig. 82. Saccobolus violascens Boud.; archicarp; after Dangeard. Fig. 83. Thehbolus stercoreus Tde.; ascocarp with single ascus, X250; after Brefeld. The species of Rhyparobius and Thelebolus, the two genera with many- spored asci, are all minute, coprophilous forms. They are distinguished by the fact that Rhyparobius produces several large asci, and Thelebolus only one (fig. 83). In both genera the cells of the mycelium are uninucleate. In Rhyparobius {Thecotheus) Pelletieri Overton has described several. Please note that these images ar

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. IV] PEZIZALES 119 orange apothecia occur on the dung of cows and rabbits, on old leather, rope and similar habitats. Chlamydospores are sometimes produced. As in Ascobolus, the archicarp is a coiled, multicellular filament; it varies considerably both in the size and number of its cells and in the amount of twisting which it undergoes. The central oogonial region includes three to seven large cells with granular contents. Between this and the parent hypha is a stalk of variable length and beyond it is a terminal portion (or trichogyne) of Stock Photo

RMRDTXRT–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. IV] PEZIZALES 119 orange apothecia occur on the dung of cows and rabbits, on old leather, rope and similar habitats. Chlamydospores are sometimes produced. As in Ascobolus, the archicarp is a coiled, multicellular filament; it varies considerably both in the size and number of its cells and in the amount of twisting which it undergoes. The central oogonial region includes three to seven large cells with granular contents. Between this and the parent hypha is a stalk of variable length and beyond it is a terminal portion (or trichogyne) of

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. ii8 DISCOMYCETES [CH.. or four cells, which diminish gradually in diameter and which he terms a trichogyne. In Ascobolus inimersus the mycelium consists of multinucleate cells, the archicarp is larger than that of A. Winteri and contains some twenty divisions, it is otherwise very similar. The cells contain numerous large nuclei and pores develop between them ; the ascogenous hyphae arise from a single cell. Ramlow observed nuclear fusions in the central cell of the archicarp, but referred them to bad fixation. His explanation may be adeq Stock Photo

RMRDTXT4–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. ii8 DISCOMYCETES [CH.. or four cells, which diminish gradually in diameter and which he terms a trichogyne. In Ascobolus inimersus the mycelium consists of multinucleate cells, the archicarp is larger than that of A. Winteri and contains some twenty divisions, it is otherwise very similar. The cells contain numerous large nuclei and pores develop between them ; the ascogenous hyphae arise from a single cell. Ramlow observed nuclear fusions in the central cell of the archicarp, but referred them to bad fixation. His explanation may be adeq

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. Fig. 102. Polysiigtnariibrztm'DC-', mature archicarp, xSoo; after Blackman and Welsford.. Fig. 103. Xylaria fioly7}iorpha (Pers.) Grev.; archicarp embedded in stroma, x looo. readily be derived from the first. It occurs in forms where the perithecium is immersed either in the substratum or in a stroma, and its essential character is the prolongation of the tip of the archicarp to form a trichogyne-like organ. The appearance of this structure is associated with the development of spermatia in spermogonia. Archicarps of the type in question Stock Photo

RMRDTNF5–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. Fig. 102. Polysiigtnariibrztm'DC-', mature archicarp, xSoo; after Blackman and Welsford.. Fig. 103. Xylaria fioly7}iorpha (Pers.) Grev.; archicarp embedded in stroma, x looo. readily be derived from the first. It occurs in forms where the perithecium is immersed either in the substratum or in a stroma, and its essential character is the prolongation of the tip of the archicarp to form a trichogyne-like organ. The appearance of this structure is associated with the development of spermatia in spermogonia. Archicarps of the type in question

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. IV] DISCOMYCETES 99 differs in its multicellular trichogyne, and oiHumariagranulata, and perhaps some other forms in which the trichogyne, like the antheridium, has dis- appeared. Another group is distinguished by the multicellular oogonial region of the archicarp, which has also a stalk and a terminal region (or trichogyne) of several cells each (fig. 58). This type of female organ is sometimes termed a scolecite. It occurs in Lachnea cretea and in several species of Asco- bolus and Ascophanus. In Ascobolus furficraceus several of the ce Stock Photo

RMRDTP22–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. IV] DISCOMYCETES 99 differs in its multicellular trichogyne, and oiHumariagranulata, and perhaps some other forms in which the trichogyne, like the antheridium, has dis- appeared. Another group is distinguished by the multicellular oogonial region of the archicarp, which has also a stalk and a terminal region (or trichogyne) of several cells each (fig. 58). This type of female organ is sometimes termed a scolecite. It occurs in Lachnea cretea and in several species of Asco- bolus and Ascophanus. In Ascobolus furficraceus several of the ce

. Botany, with agricultural applications. Botany. Fig. 348.—a Bird's Nest Fungus, Nidvlaria. About natural size. organic matter in the ground. The sporophore is at first globose, but the gleba soon breaks out of the peridium and is elevated to some distance above ground by an elongating stalk. The spore masses are slimy and have the odor of carrion. Certain insects which dissemi- nate the spores are attracted by the odor. Smuts (Ustilaginales).—The Smuts are parasitic Basidiomycetes. In some Smuts, the mycelium, although evident only in local areas, traverses widely through the host, while in Stock Photo

RMRDWCXK–. Botany, with agricultural applications. Botany. Fig. 348.—a Bird's Nest Fungus, Nidvlaria. About natural size. organic matter in the ground. The sporophore is at first globose, but the gleba soon breaks out of the peridium and is elevated to some distance above ground by an elongating stalk. The spore masses are slimy and have the odor of carrion. Certain insects which dissemi- nate the spores are attracted by the odor. Smuts (Ustilaginales).—The Smuts are parasitic Basidiomycetes. In some Smuts, the mycelium, although evident only in local areas, traverses widely through the host, while in

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 214 PROTOBASIDIOMYCETES [CH. fertile cells of Phragmidium violacetun was shown by Blackman and subse- quently by Welsford to be derived from one of the smaller cells at the base of the fertile layer. It is thus a vegetative nucleus; it enters the fertile cell by migrating through the wall, becoming much drawn out and laterally com- pressed. It leaves a pore which may be identified after its passage (fig. 192).. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - colo Stock Photo

RMRDX0FN–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 214 PROTOBASIDIOMYCETES [CH. fertile cells of Phragmidium violacetun was shown by Blackman and subse- quently by Welsford to be derived from one of the smaller cells at the base of the fertile layer. It is thus a vegetative nucleus; it enters the fertile cell by migrating through the wall, becoming much drawn out and laterally com- pressed. It leaves a pore which may be identified after its passage (fig. 192).. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - colo

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. VII] USTILAGINALES 193 uninucleate or binucleate (fig. 160), but it is not known whether fusion takes place in them. The multinucleate character of the mycelial cells strongly suggests that no preliminary pairing of the nuclei occurs. In Ustilago Zeae Lutman also observed a mycelium of multinucleate cells; at the time of spore-formation binucleate and uninucleate cells and finally uninucleate spores appear. Tilletiaceae The principal genera of the Tilletiaceae are Tilletia,Entylofna, Tuburcinia, Urocystis and Doassansia. They have in comm Stock Photo

RMRDX0TX–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. VII] USTILAGINALES 193 uninucleate or binucleate (fig. 160), but it is not known whether fusion takes place in them. The multinucleate character of the mycelial cells strongly suggests that no preliminary pairing of the nuclei occurs. In Ustilago Zeae Lutman also observed a mycelium of multinucleate cells; at the time of spore-formation binucleate and uninucleate cells and finally uninucleate spores appear. Tilletiaceae The principal genera of the Tilletiaceae are Tilletia,Entylofna, Tuburcinia, Urocystis and Doassansia. They have in comm

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. V] LABOULBENIALES 175 the appendages aside and take up an apparently terminal position. The development is very uniform, and has been described by Thaxter in some detail for Stigmatomyces Baeri. Here, the upper cell of the receptacle divides into two; the lower of these remains as part of the receptacle, and the upper grows out (fig. -},6d) to form the female organ and ultimately. Fig. 136. Stigmatomyces Baeri Peyritsch ; development of the perithecium; a. shows the two-celled receptacle, a single appendage bearing five simple, endogenou Stock Photo

RMRDX13N–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. V] LABOULBENIALES 175 the appendages aside and take up an apparently terminal position. The development is very uniform, and has been described by Thaxter in some detail for Stigmatomyces Baeri. Here, the upper cell of the receptacle divides into two; the lower of these remains as part of the receptacle, and the upper grows out (fig. -},6d) to form the female organ and ultimately. Fig. 136. Stigmatomyces Baeri Peyritsch ; development of the perithecium; a. shows the two-celled receptacle, a single appendage bearing five simple, endogenou

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. in] PLECTASCALES 73 enclosed them between glass plates so as to reduce the entrance of air, and the development of conidia. Similarly Zukal a few years later obtained sclerotia by excluding air. The formation of the perithecia in Brefeld's material was initiated by the appearance of pairs of simple, stout hyphae which twisted round one another (fig. 32), and from one or both of which branches later arose. Brefeld regarded them as possibly oogonial and antheridial. A further study of these organs, the simple form of which suggests a compar Stock Photo

RMRDTP7N–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. in] PLECTASCALES 73 enclosed them between glass plates so as to reduce the entrance of air, and the development of conidia. Similarly Zukal a few years later obtained sclerotia by excluding air. The formation of the perithecia in Brefeld's material was initiated by the appearance of pairs of simple, stout hyphae which twisted round one another (fig. 32), and from one or both of which branches later arose. Brefeld regarded them as possibly oogonial and antheridial. A further study of these organs, the simple form of which suggests a compar

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 176 PYRENOMYCETES [CH. All the cells are uninucleate. The female cell is called by Thaxter a carpogonium or carpogonic cell in conformity with the term used for the Red Algae, but it obviously corresponds to the cell in which fertilization is now known to occur in other Ascomycetes and will therefore here be termed the oogonium. In Stigmatomyccs Baeri the trichogyne is simple (fig. 136^, e) but in many other members of the group it undergoes frequent septation and branches freely. The apices of the branches are alone receptive and may str Stock Photo

RMRDX13C–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 176 PYRENOMYCETES [CH. All the cells are uninucleate. The female cell is called by Thaxter a carpogonium or carpogonic cell in conformity with the term used for the Red Algae, but it obviously corresponds to the cell in which fertilization is now known to occur in other Ascomycetes and will therefore here be termed the oogonium. In Stigmatomyccs Baeri the trichogyne is simple (fig. 136^, e) but in many other members of the group it undergoes frequent septation and branches freely. The apices of the branches are alone receptive and may str

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. n] ASCOMYCETES 47 four. Further the adhesion of chromosomes already described for Phyllac- tinia must not be forgotten. The occurrence of paired nuclei in the ascogenous hyphae was thus the most important evidence in favour of Claussen's view until in 1916 Welsford showed that the nuclei even of gametophytic, multinucleate hyphae are habitually paired if rapid growth and division are taking place; this is due to the fact that mitoses follow one another so rapidly that the daughter nuclei of any parti- cular division have not time to move Stock Photo

RMRDX1NC–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. n] ASCOMYCETES 47 four. Further the adhesion of chromosomes already described for Phyllac- tinia must not be forgotten. The occurrence of paired nuclei in the ascogenous hyphae was thus the most important evidence in favour of Claussen's view until in 1916 Welsford showed that the nuclei even of gametophytic, multinucleate hyphae are habitually paired if rapid growth and division are taking place; this is due to the fact that mitoses follow one another so rapidly that the daughter nuclei of any parti- cular division have not time to move

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 70 PLECTOMYCETES [CH. the outer filaments form four or five parenchymatous layers which constitute a protective sheath, apparently differing but little from that of Eurotium or Penicillium. In the investigated species of the genus Eurotium (^Aspergillus), the ascospores and conidia are commonly multinucleate and give rise on ger- mination to a septate mycelium each cell of which contains several nuclei. Conidiophores appear early; they arise as a rule from densely tangled knots of swollen mycelium, and appear as thick, multinucleate hypha Stock Photo

RMRDX1HW–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 70 PLECTOMYCETES [CH. the outer filaments form four or five parenchymatous layers which constitute a protective sheath, apparently differing but little from that of Eurotium or Penicillium. In the investigated species of the genus Eurotium (^Aspergillus), the ascospores and conidia are commonly multinucleate and give rise on ger- mination to a septate mycelium each cell of which contains several nuclei. Conidiophores appear early; they arise as a rule from densely tangled knots of swollen mycelium, and appear as thick, multinucleate hypha

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. V] SPHAERIALES 157 long hairs around the ostiole, and from the Sphaeriaceae in the habitat and type of spore. The mycehum is in most cases composed of multinucleate cells, but in Podospora hirsuta the cells are uninucleate (fig. 115), recalling the condition in several species of Chaetomium. The commonest type of archicarp is a stout, coiled, septate hypha which soon becomes surrounded by vegetative filaments; it is usually terminal, but is occasionally intercalary, for instance in Sordaria fimicola. Dangeard has found a straight archicar Stock Photo

RMRDTNBB–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. V] SPHAERIALES 157 long hairs around the ostiole, and from the Sphaeriaceae in the habitat and type of spore. The mycehum is in most cases composed of multinucleate cells, but in Podospora hirsuta the cells are uninucleate (fig. 115), recalling the condition in several species of Chaetomium. The commonest type of archicarp is a stout, coiled, septate hypha which soon becomes surrounded by vegetative filaments; it is usually terminal, but is occasionally intercalary, for instance in Sordaria fimicola. Dangeard has found a straight archicar

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. Fig. 170. Uromyces Poae'R&h&n.; aecidium just before the epidermis is broljen through, x 310; after Black- man and Fraser. Pliragmitis. A corresponding discoloration takes place around the young aecidia, and there is thus some suggestion that the spermatia, when functional, were carried to their destination by insects. The aecidia occur in groups, usually on the abaxial side of the leaf; in them the aecidiospores are produced in basipetal rows (fig. 170) alternating with small, abortive, intercalary cells, by the disintegration of Stock Photo

RMRDX0P1–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. Fig. 170. Uromyces Poae'R&h&n.; aecidium just before the epidermis is broljen through, x 310; after Black- man and Fraser. Pliragmitis. A corresponding discoloration takes place around the young aecidia, and there is thus some suggestion that the spermatia, when functional, were carried to their destination by insects. The aecidia occur in groups, usually on the abaxial side of the leaf; in them the aecidiospores are produced in basipetal rows (fig. 170) alternating with small, abortive, intercalary cells, by the disintegration of

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. IV] PEZIZALES lOI Pyronemaceae The Pyronemaceae are a small group distinguished from the other Pezizales by the fact that the peridium, or lateral boundary of protective hyphae around the fruit, is not well developed. This is not always regarded as a sufficiently important character to warrant their separation from the Pezizaceae and many authors include them in that group. The only important genera are Ascodesrnis and Pyronema, species of both of which have been somewhat fully investigated. Ascodesrnis nigricans'' (fig. 59) is a small co Stock Photo

RMRDTP1W–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. IV] PEZIZALES lOI Pyronemaceae The Pyronemaceae are a small group distinguished from the other Pezizales by the fact that the peridium, or lateral boundary of protective hyphae around the fruit, is not well developed. This is not always regarded as a sufficiently important character to warrant their separation from the Pezizaceae and many authors include them in that group. The only important genera are Ascodesrnis and Pyronema, species of both of which have been somewhat fully investigated. Ascodesrnis nigricans'' (fig. 59) is a small co

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. V] LABOULBENIALES 173 monoecious forms) bears the appendages in a terminal position and the perithecium laterally (fig. 136). More rarely the receptacle consists of a larger number of cells variously arranged and reaching a considerable complexity in such forms as Zodio- myces vorticellarius (fig. 133). One or more appendages are borne on the receptacle. These are more or less filamentous and often elaborately branched. They bear the male organs and serve also for the protection of the delicate trichogyne and perhaps facilitate fertilizat Stock Photo

RMRDX143–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. V] LABOULBENIALES 173 monoecious forms) bears the appendages in a terminal position and the perithecium laterally (fig. 136). More rarely the receptacle consists of a larger number of cells variously arranged and reaching a considerable complexity in such forms as Zodio- myces vorticellarius (fig. 133). One or more appendages are borne on the receptacle. These are more or less filamentous and often elaborately branched. They bear the male organs and serve also for the protection of the delicate trichogyne and perhaps facilitate fertilizat

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. V] SPHAERIALES iSS Chaetoniiaceae The Chaetomiaceae occur on straw, paper, dung and other waste materials; they possess free, thin-walled perithecia beset with numerous characteristic, long hairs (fig. 112), which are often elaborately branched or coiled. On these, or on the ordinary vegetative mycelium, conidia are produced. An ostiole is lacking in Ch. fimete, presumably the most primitive member of the genus; in the remaining species it is present and the peri- thecium is of the typical sphaeriaceous form. In Chaetomium spirale the cel Stock Photo

RMRDTNBX–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. V] SPHAERIALES iSS Chaetoniiaceae The Chaetomiaceae occur on straw, paper, dung and other waste materials; they possess free, thin-walled perithecia beset with numerous characteristic, long hairs (fig. 112), which are often elaborately branched or coiled. On these, or on the ordinary vegetative mycelium, conidia are produced. An ostiole is lacking in Ch. fimete, presumably the most primitive member of the genus; in the remaining species it is present and the peri- thecium is of the typical sphaeriaceous form. In Chaetomium spirale the cel

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. IV] PEZIZALES 103 oogonium, from which a trichogyne protruded (fig. 61 b). The union of the trichogyne and antheridium was observed and it was shown that from the oogonium ascogenous hyphae subsequently arose. Van Tieghem recorded that the species is very susceptible to external conditions, the antheridium sometimes being reduced in size or absent, though the oogonium nevertheless developed normally and produced ascogenous hyphae. In 1900 appeared the classical researches of Harper, followed in 1903 and 1907 by Dangeard's, and in 1912 by Stock Photo

RMRDTP1D–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. IV] PEZIZALES 103 oogonium, from which a trichogyne protruded (fig. 61 b). The union of the trichogyne and antheridium was observed and it was shown that from the oogonium ascogenous hyphae subsequently arose. Van Tieghem recorded that the species is very susceptible to external conditions, the antheridium sometimes being reduced in size or absent, though the oogonium nevertheless developed normally and produced ascogenous hyphae. In 1900 appeared the classical researches of Harper, followed in 1903 and 1907 by Dangeard's, and in 1912 by

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. V] SPHAERIALES 159 rotia which originate in the cortex of the host root; reproduction is by means of conidia formed in summer on the surface of the soil, and further by ascospores produced in perithecia. Hartig has found that the perithecium is initiated by the development of a pair of thick hyphae rich in contents. These become enclosed within a mass of vegetative tissue, but their subse- quent behaviour has not been determined, and no details of development are known either here or in other members of the family. SPHAERIACEAE : BIBLIOGR Stock Photo

RMRDTNA8–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. V] SPHAERIALES 159 rotia which originate in the cortex of the host root; reproduction is by means of conidia formed in summer on the surface of the soil, and further by ascospores produced in perithecia. Hartig has found that the perithecium is initiated by the development of a pair of thick hyphae rich in contents. These become enclosed within a mass of vegetative tissue, but their subse- quent behaviour has not been determined, and no details of development are known either here or in other members of the family. SPHAERIACEAE : BIBLIOGR

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. IV] PHACIDIALES 133 of calcium oxalate; when the fruit opens it forms a white border around the hymenium. The pale colour, and the ragged or tppthed dehiscence of the sheath are very characteristic. Phacidiaceae The Phacidiaceae are distinguished by their black, thick-walled apothecia, usually scattered, sometimes, as in Rkytisma, grouped on a black stroma. Where the fertile disc is circular the sheath splits in a stellate manner, but where it is elongated, dehiscence takes place by means of a slit running along its entire length. The spe Stock Photo

RMRDTNJ0–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. IV] PHACIDIALES 133 of calcium oxalate; when the fruit opens it forms a white border around the hymenium. The pale colour, and the ragged or tppthed dehiscence of the sheath are very characteristic. Phacidiaceae The Phacidiaceae are distinguished by their black, thick-walled apothecia, usually scattered, sometimes, as in Rkytisma, grouped on a black stroma. Where the fertile disc is circular the sheath splits in a stellate manner, but where it is elongated, dehiscence takes place by means of a slit running along its entire length. The spe

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. VIIl] UREDINALES 205 produce a second type of uredospore with thick walls which are adapted to survive unfavourable conditions; these are known as amphispores. Both aecidio- and uredospores germinate readily and without a rest if fully ripe, but many are shaken off by wind and rain before they reach maturity and remain incapable of germination. Moreover it is stated that spores will not ripen properly on leaves that have been removed from the plant. Sooner or later the mycelium of binucleate cells gives rise to teleuto- spores; these are Stock Photo

RMRDX0JR–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. VIIl] UREDINALES 205 produce a second type of uredospore with thick walls which are adapted to survive unfavourable conditions; these are known as amphispores. Both aecidio- and uredospores germinate readily and without a rest if fully ripe, but many are shaken off by wind and rain before they reach maturity and remain incapable of germination. Moreover it is stated that spores will not ripen properly on leaves that have been removed from the plant. Sooner or later the mycelium of binucleate cells gives rise to teleuto- spores; these are

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. Ill ASCOMYCETES 45 was proposed. The occurrence of a brachymeiotic reduction has since been observed in several other fungi, and has also been in several cases denied. Chromosome Association. There are a number of fungi, of which Phyllactinia Corylea is perhaps the most fully studied, in which no change in the chromosome number takes place throughout the life-history. In Phyl- lactinia, Harper showed in 1905 that the chromosomes remain visible in strands attached to the central body throughout the resting stages. In each of the nuclei of Stock Photo

RMRDX1P8–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. Ill ASCOMYCETES 45 was proposed. The occurrence of a brachymeiotic reduction has since been observed in several other fungi, and has also been in several cases denied. Chromosome Association. There are a number of fungi, of which Phyllactinia Corylea is perhaps the most fully studied, in which no change in the chromosome number takes place throughout the life-history. In Phyl- lactinia, Harper showed in 1905 that the chromosomes remain visible in strands attached to the central body throughout the resting stages. In each of the nuclei of

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. CHAPTER V PYRENOMYCETES The Pyrenomycetes include some 10,000 species; they are characterized by the fact that their ascocarp or perithecium is a more or less flask-shaped organ opening by a narrow pore, the ostiole, and containing a hymenium spread in a regular manner over the floor and lower part ofthesides (fig. 100). It thus differs from the perithecium of the higher Plectascales where the asci are irregularly scat- tered, and from that of the Erysiphales where, except in the flattened perithecium of the Microthyriaceae, an ostiole is Stock Photo

RMRDTNFP–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. CHAPTER V PYRENOMYCETES The Pyrenomycetes include some 10,000 species; they are characterized by the fact that their ascocarp or perithecium is a more or less flask-shaped organ opening by a narrow pore, the ostiole, and containing a hymenium spread in a regular manner over the floor and lower part ofthesides (fig. 100). It thus differs from the perithecium of the higher Plectascales where the asci are irregularly scat- tered, and from that of the Erysiphales where, except in the flattened perithecium of the Microthyriaceae, an ostiole is

. Botany, with agricultural applications. Botany. 392 THALLOPHYTES. Fig. 348.—a Bird's Nest Fungus, Nidvlaria. About natural size. organic matter in the ground. The sporophore is at first globose, but the gleba soon breaks out of the peridium and is elevated to some distance above ground by an elongating stalk. The spore masses are slimy and have the odor of carrion. Certain insects which dissemi- nate the spores are attracted by the odor. Smuts (Ustilaginales).—The Smuts are parasitic Basidiomycetes. In some Smuts, the mycelium, although evident only in local areas, traverses widely through t Stock Photo

RMRDWCXN–. Botany, with agricultural applications. Botany. 392 THALLOPHYTES. Fig. 348.—a Bird's Nest Fungus, Nidvlaria. About natural size. organic matter in the ground. The sporophore is at first globose, but the gleba soon breaks out of the peridium and is elevated to some distance above ground by an elongating stalk. The spore masses are slimy and have the odor of carrion. Certain insects which dissemi- nate the spores are attracted by the odor. Smuts (Ustilaginales).—The Smuts are parasitic Basidiomycetes. In some Smuts, the mycelium, although evident only in local areas, traverses widely through t

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. n] ASCOMYCETES 39 (i-«-.. hymenium. In Desmotascus^, a pyrenomycetous fungus parasitic on Bromelia, the paraphyses are replaced by a thin-walled pseudoparenchyma recalling the arrangement in the higher Plectomycetes. The Peridium. The peridium or wall of the ascocarp is a weft of sterile hyphae in which the individual filamentsare sometimes clear- '^- ly distinguished, sometimes closely interwoven to form a pseudoparenchyma; the walls of the outer cells are some- times considerably thickened and may be variously pig- mented ; in many case Stock Photo

RMRDX1TR–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. n] ASCOMYCETES 39 (i-«-.. hymenium. In Desmotascus^, a pyrenomycetous fungus parasitic on Bromelia, the paraphyses are replaced by a thin-walled pseudoparenchyma recalling the arrangement in the higher Plectomycetes. The Peridium. The peridium or wall of the ascocarp is a weft of sterile hyphae in which the individual filamentsare sometimes clear- '^- ly distinguished, sometimes closely interwoven to form a pseudoparenchyma; the walls of the outer cells are some- times considerably thickened and may be variously pig- mented ; in many case

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 96 DISCOMYCETES [CH. the sides and bottom of the cup. In many cases, as in Pesiza vesiculosa and Otidea aurantia, the cup is small and comparatively full when it first opens, and grows larger and deeper as development proceeds.. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Gwynne-Vaughan, Helen Charlotte Isabella (Fraser) Dame, 1879-. Cambridge [Eng] University Pres Stock Photo

RMRDTP33–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 96 DISCOMYCETES [CH. the sides and bottom of the cup. In many cases, as in Pesiza vesiculosa and Otidea aurantia, the cup is small and comparatively full when it first opens, and grows larger and deeper as development proceeds.. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Gwynne-Vaughan, Helen Charlotte Isabella (Fraser) Dame, 1879-. Cambridge [Eng] University Pres

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 178 PYRENOMYCETES [CH. 5". There is an obvious suggestion in these phenomena of a transition between the monoecious and dioecious condition but it is not clear in which direction the series should be read. It might be inferred that the male plant had become atro- phied after the female had acquired spermatial organs, or on the other hand that, as in many other groups of plants, a hermaphrodite con- dition was primitive and segregation a later development. Ainorphomyces Falagriae may be taken as an example of a dioecious form which sh Stock Photo

RMRDX127–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 178 PYRENOMYCETES [CH. 5". There is an obvious suggestion in these phenomena of a transition between the monoecious and dioecious condition but it is not clear in which direction the series should be read. It might be inferred that the male plant had become atro- phied after the female had acquired spermatial organs, or on the other hand that, as in many other groups of plants, a hermaphrodite con- dition was primitive and segregation a later development. Ainorphomyces Falagriae may be taken as an example of a dioecious form which sh

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. V] SPHAERIALES i6i Pleosporaceae The Pleosporaceae are saprophytes or in a few cases parasites, for the most part on seed plants but in some cases on Pteridophyta, Bryophyta or Lichens. The perithecia are immersed in the substratum, the ostiole only projecting, but they may become more or less exposed by the rupture of the covering tissues. The peridium is leathery or membranous. The genus Pleospora includes some 225 species, several of which occur on grains and other grasses where they show biological specialization. Pleospora herbarum i Stock Photo

RMRDTNA1–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. V] SPHAERIALES i6i Pleosporaceae The Pleosporaceae are saprophytes or in a few cases parasites, for the most part on seed plants but in some cases on Pteridophyta, Bryophyta or Lichens. The perithecia are immersed in the substratum, the ostiole only projecting, but they may become more or less exposed by the rupture of the covering tissues. The peridium is leathery or membranous. The genus Pleospora includes some 225 species, several of which occur on grains and other grasses where they show biological specialization. Pleospora herbarum i

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. IV] TUBERALES 137 Bucholtz was able to examine, showed a system of internal chambers lined by the hymenium and communi- cating at one or more points with the exterior. As development pro- ceeds these cavities increase in size and the hymenium becomes further convoluted, so that additional cham- bers are formed. In Tuber the ascocarp is ir- regularly globose, fleshy or some- times almost woody; internally the walls which divide the gleba are extensively branched, and the free space between them is diminished, so that the layers of the hyme Stock Photo

RMRDTNG4–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. IV] TUBERALES 137 Bucholtz was able to examine, showed a system of internal chambers lined by the hymenium and communi- cating at one or more points with the exterior. As development pro- ceeds these cavities increase in size and the hymenium becomes further convoluted, so that additional cham- bers are formed. In Tuber the ascocarp is ir- regularly globose, fleshy or some- times almost woody; internally the walls which divide the gleba are extensively branched, and the free space between them is diminished, so that the layers of the hyme

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. ERYSIPHALES 85 III] The antheridial branch is much narrower; it applies itself to the side of the oogonium and when first cut off contains a single nucleus (fig. 41 a). It is clearly differentiated from the hyphae of the sheath not only by its form and behaviour but by its much earlier appearance and definite relation to the oogonium. Its nucleus soon divides ; one of the daughter nuclei passes to the apex of the branch and a wall is formed cutting off the uni- nucleate antheridium. The oogonial nucleus is rather larger than those of the Stock Photo

RMRDTP5N–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. ERYSIPHALES 85 III] The antheridial branch is much narrower; it applies itself to the side of the oogonium and when first cut off contains a single nucleus (fig. 41 a). It is clearly differentiated from the hyphae of the sheath not only by its form and behaviour but by its much earlier appearance and definite relation to the oogonium. Its nucleus soon divides ; one of the daughter nuclei passes to the apex of the branch and a wall is formed cutting off the uni- nucleate antheridium. The oogonial nucleus is rather larger than those of the

RMRDX0XN–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. VIl] USTILAGINALES 187 In the regions where the formation of brand-spores is to take place, the mycehum becomes richly branched and often swollen and gelatinous. In Ustilago and Sphacelotheca the sporogenous hyphae are divided into a number of short segments in each of which the contents form a spore surrounded by an independent membrane. The spores are enclosed at first within the gelatinous parent walls, but later these disappear so that the whole mycelium is transformed into a pulverulent mass of spores. In Tilletia and Entyloma the sp

RMRDX10E–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. CH. VIl] USTILAGI'NALES i8s The mature brand-spore is uninucleate, and is surrounded by a delicate endospore and by an epispore which may be smooth or variously sculptured and usually contains pigment, giving the spore a black, brown, or violet colour. On germination the spore gives rise to a short tube, the promycelium or basidium (fig. 147), into which its contents pass, the nucleus undergoing at. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and a

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. "] ASCOMYCETES 43 continuation of the ascogenous hypha, and gives rise to fresh asci (fig. lo). This process was first recorded in 1908 for Humaria rtttilans and has since been observed by McCubbin in Helvella elastica, by Carruthers in Helvetia crispa, and by Claussen in Pyronema confliiens. It suggests either that some advantage is to be derived from an absence of relationship between the nuclei which fuse in the ascus, or that a scheme of rigid nuclear economy is in force. The former hypothesis is somewhat weakened by the fact tha Stock Photo

RMRDX1PN–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. "] ASCOMYCETES 43 continuation of the ascogenous hypha, and gives rise to fresh asci (fig. lo). This process was first recorded in 1908 for Humaria rtttilans and has since been observed by McCubbin in Helvella elastica, by Carruthers in Helvetia crispa, and by Claussen in Pyronema confliiens. It suggests either that some advantage is to be derived from an absence of relationship between the nuclei which fuse in the ascus, or that a scheme of rigid nuclear economy is in force. The former hypothesis is somewhat weakened by the fact tha

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. IV] TUBERALES 135 TUBERALES The Tuberales are typically subterranean though some species are only imperfectly buried, or grow among decaying leaves. When mature the fruits emit a powerful odour by which rodents are apprised of their where- abouts. The ascocarp is eaten and the spores dispersed after passing through the alimentary canal of the animal. The ascocarp is more or less globose, sometimes completely closed, sometimes with a small opening. The hymenium may form a smooth lining to the fruit or may be thrown into elaborate folds so Stock Photo

RMRDTNHP–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. IV] TUBERALES 135 TUBERALES The Tuberales are typically subterranean though some species are only imperfectly buried, or grow among decaying leaves. When mature the fruits emit a powerful odour by which rodents are apprised of their where- abouts. The ascocarp is eaten and the spores dispersed after passing through the alimentary canal of the animal. The ascocarp is more or less globose, sometimes completely closed, sometimes with a small opening. The hymenium may form a smooth lining to the fruit or may be thrown into elaborate folds so

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. IV] PEZIZALES 105 While the formation of the pore is in progress the nuclei of the tricho- gyne degenerate, and, by the time that they are completely disorganized, a migration of the male nuclei through the pore begins. Ultimately the contents of the trichogyne degenerate still further, till the cytoplasm and nuclei together form a densely staining mass which may be recognized even in the mature fruit. The male nuclei continue to pass into the tube until it is densely filled, and sometimes a trifle swollen. According to most observers the Stock Photo

RMRDTP0X–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. IV] PEZIZALES 105 While the formation of the pore is in progress the nuclei of the tricho- gyne degenerate, and, by the time that they are completely disorganized, a migration of the male nuclei through the pore begins. Ultimately the contents of the trichogyne degenerate still further, till the cytoplasm and nuclei together form a densely staining mass which may be recognized even in the mature fruit. The male nuclei continue to pass into the tube until it is densely filled, and sometimes a trifle swollen. According to most observers the

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. IV] PEZIZALES "7 as twenty (Dodge), sometimes a much smaller number of cells. These are at first uninucleate (Harper, Welsford), or multinucleate (Dangeard); later they always contain numerous nuclei (fig. 76 a). One of them, usually the. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Gwynne-Vaughan, Helen Charlotte Isabella (Fraser) Dame, 1879-. Cambridge [Eng] Stock Photo

RMRDTNPB–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. IV] PEZIZALES "7 as twenty (Dodge), sometimes a much smaller number of cells. These are at first uninucleate (Harper, Welsford), or multinucleate (Dangeard); later they always contain numerous nuclei (fig. 76 a). One of them, usually the. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Gwynne-Vaughan, Helen Charlotte Isabella (Fraser) Dame, 1879-. Cambridge [Eng]

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. Fig. 143. Amorphomyces FalagriaeT'3.yite'c; male and female individuals; a. young, b. mature; after Thaxter. Walls cut off the upper and the lower nucleus, and a central binucleate cell is left, the lower nucleus of which is presumably a daughter of the oogonial and the upper of the trichophoric nucleus. These divide simultaneously and a binucleate inferior sterile cell is separated from the binucleate fertile cell. This in turn divides to form the ascogenic cells, from which the asci are to develop, and these and the asci which they pr Stock Photo

RMRDX11R–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. Fig. 143. Amorphomyces FalagriaeT'3.yite'c; male and female individuals; a. young, b. mature; after Thaxter. Walls cut off the upper and the lower nucleus, and a central binucleate cell is left, the lower nucleus of which is presumably a daughter of the oogonial and the upper of the trichophoric nucleus. These divide simultaneously and a binucleate inferior sterile cell is separated from the binucleate fertile cell. This in turn divides to form the ascogenic cells, from which the asci are to develop, and these and the asci which they pr

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. IV] HELVELLALES 131 Geoglossaceae The Geoglossaceae grow usually in damp or moist situations such as low, wet woods and shady slopes. They occur on soil or on dead branches or leaves, and two species of Mitrula are parasitic on living moss. The family includes some eight genera of which five are British.. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Gwynne-Vaughan, Stock Photo

RMRDTNJG–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. IV] HELVELLALES 131 Geoglossaceae The Geoglossaceae grow usually in damp or moist situations such as low, wet woods and shady slopes. They occur on soil or on dead branches or leaves, and two species of Mitrula are parasitic on living moss. The family includes some eight genera of which five are British.. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Gwynne-Vaughan,

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. Fig. 186. Endofhyllum Setnpervivi'L&v.; spores giving rise to basidia; both after Hoffmann. (fig. 186); its two nuclei fuse (fig. 187), its contents are extruded as a pro- mycelium, two successive nuclear divisions occur, cross walls appear and four basidiospores are produced, which, in due course, give rise to a uninucleate mycelium. The sporophytic stage thus endures only from the fusion of the fertile cells until the germination of the spores which they produce. Incidentally these observations in the case of Kunkelia nitens have de Stock Photo

RMRDX0H3–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. Fig. 186. Endofhyllum Setnpervivi'L&v.; spores giving rise to basidia; both after Hoffmann. (fig. 186); its two nuclei fuse (fig. 187), its contents are extruded as a pro- mycelium, two successive nuclear divisions occur, cross walls appear and four basidiospores are produced, which, in due course, give rise to a uninucleate mycelium. The sporophytic stage thus endures only from the fusion of the fertile cells until the germination of the spores which they produce. Incidentally these observations in the case of Kunkelia nitens have de

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. V] HYPOCREALES 145 merit of the sheath has begun, may correspond to the septation of the fertihzed oogonium in other forms. Further, the origin of the asci from a single cell points to the Erysiphales and Laboulbeniales, and in view of the longitudinal divisions, perhaps especially to the latter. In Nectria the usually red or yellow perithecia are produced in groups on stromata of the same colour; the asci contain eight ascospores which are two- celled, and often produce conidia by budding while still in the ascus. The genus is large, inc Stock Photo

RMRDTNE3–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. V] HYPOCREALES 145 merit of the sheath has begun, may correspond to the septation of the fertihzed oogonium in other forms. Further, the origin of the asci from a single cell points to the Erysiphales and Laboulbeniales, and in view of the longitudinal divisions, perhaps especially to the latter. In Nectria the usually red or yellow perithecia are produced in groups on stromata of the same colour; the asci contain eight ascospores which are two- celled, and often produce conidia by budding while still in the ascus. The genus is large, inc

RMRDX0WE–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. Federley, in 1903, described specimens of this fungus in which conjugation is followed not only by the migration of the nucleus of one of the cells concerned, but also by nuclear fusion (fig. 15s). In view of the fusion in the young spore recorded by Dangeard and by Rawitscher the details of de- velopment in this species de- mand further investigation. Ustilago Maydis, the smut of Zea Mays, induces con- siderable hypertrophy. The deformations contain a mass of gelatinous mycelium from which brand-spores are produced. When mature, the spor

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. »--/. '@^..?>^^- Fig. 62. Pyronema confltiens a. antheridium, trichogyne and oogoniutiH- male and female nuclei collected in the middle of the latter; b. c. fusion of male and female nuclei; after Harper. spread out into the cytoplasm of the beak, suggesting that the solvent action is mainly exerted from the interior of the, trichogyne. The open pore now becomes thickened around its margin so that an exceedingly strong ring unites the antheridium and trichogyne, and they can be bent or turned upon each other without being pulled apar Stock Photo

RMRDTP13–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. »--/. '@^..?>^^- Fig. 62. Pyronema confltiens a. antheridium, trichogyne and oogoniutiH- male and female nuclei collected in the middle of the latter; b. c. fusion of male and female nuclei; after Harper. spread out into the cytoplasm of the beak, suggesting that the solvent action is mainly exerted from the interior of the, trichogyne. The open pore now becomes thickened around its margin so that an exceedingly strong ring unites the antheridium and trichogyne, and they can be bent or turned upon each other without being pulled apar

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. cytoplasm forming the primordium of a;spore. In 1879 Schmitz observed nuclei in the vegetative cells of several Ascomycetes, and in 1893 Gjurasin in Peziza vesiculosa recognized that the divisions in the ascus are karyokinetic. The Fusion in the Ascus. In 1894, Dangeard showed in Peziza vesi- culosa and other forms with a well-developed fructification, that the ascus at its first inception is binucleate and that the two nuclei subsequently unite to form the definitive nucleus of de Bary.. He at first believed that the ascus was produced i Stock Photo

RMRDX1RX–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. cytoplasm forming the primordium of a;spore. In 1879 Schmitz observed nuclei in the vegetative cells of several Ascomycetes, and in 1893 Gjurasin in Peziza vesiculosa recognized that the divisions in the ascus are karyokinetic. The Fusion in the Ascus. In 1894, Dangeard showed in Peziza vesi- culosa and other forms with a well-developed fructification, that the ascus at its first inception is binucleate and that the two nuclei subsequently unite to form the definitive nucleus of de Bary.. He at first believed that the ascus was produced i

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. Ill] PLECTASCALES 6i W. decolorans has been identified by van der Wolk as the cause of "yellow grains," a serious disease of stored rice which is endemic in the East Indies and elsewhere, but is prevented by attention to thoroughly dry conditions. The only known species of Dipodascus, D. albidus, was discovered by de Lagerheim in Quinto in 1892 on the gummy secretion of Puya, one of the Bromeliaceae. It was found again in 1901 by Juel, in Sweden, on the sap of an injured birch, and has been described by both these investigators Stock Photo

RMRDX1JY–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. Ill] PLECTASCALES 6i W. decolorans has been identified by van der Wolk as the cause of "yellow grains," a serious disease of stored rice which is endemic in the East Indies and elsewhere, but is prevented by attention to thoroughly dry conditions. The only known species of Dipodascus, D. albidus, was discovered by de Lagerheim in Quinto in 1892 on the gummy secretion of Puya, one of the Bromeliaceae. It was found again in 1901 by Juel, in Sweden, on the sap of an injured birch, and has been described by both these investigators

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 200 PROTOBASIDIOMYCETES [CH.. Fig. 170. Uromyces Poae'R&h&n.; aecidium just before the epidermis is broljen through, x 310; after Black- man and Fraser. Pliragmitis. A corresponding discoloration takes place around the young aecidia, and there is thus some suggestion that the spermatia, when functional, were carried to their destination by insects. The aecidia occur in groups, usually on the abaxial side of the leaf; in them the aecidiospores are produced in basipetal rows (fig. 170) alternating with small, abortive, intercalary c Stock Photo

RMRDX0P7–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 200 PROTOBASIDIOMYCETES [CH.. Fig. 170. Uromyces Poae'R&h&n.; aecidium just before the epidermis is broljen through, x 310; after Black- man and Fraser. Pliragmitis. A corresponding discoloration takes place around the young aecidia, and there is thus some suggestion that the spermatia, when functional, were carried to their destination by insects. The aecidia occur in groups, usually on the abaxial side of the leaf; in them the aecidiospores are produced in basipetal rows (fig. 170) alternating with small, abortive, intercalary c

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. Fig. 106. Polystigvia ritbruni DC.; sper- mogonium, x 250; after Blackmanand Welsford. Fig. 107. Polystigma ruhrum DC; vege- tative hj'phae projecting through stoma above archicarp, x 900 ; after Blaclcman and Welsford. trichogynes, but Blackman and Welsford, and later Nienburg, failed to trace any connection between them and the coiled archicarps. On the contrary, the latter end blindly within the stroma with or without branching, and it is only quite occasionally that they can even be traced upwards towards the stomata. Nienburg observe Stock Photo

RMRDTNDJ–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. Fig. 106. Polystigvia ritbruni DC.; sper- mogonium, x 250; after Blackmanand Welsford. Fig. 107. Polystigma ruhrum DC; vege- tative hj'phae projecting through stoma above archicarp, x 900 ; after Blaclcman and Welsford. trichogynes, but Blackman and Welsford, and later Nienburg, failed to trace any connection between them and the coiled archicarps. On the contrary, the latter end blindly within the stroma with or without branching, and it is only quite occasionally that they can even be traced upwards towards the stomata. Nienburg observe

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 86 PLECTOMYCETES [CH. chromosomes is that of Winge who describes eight in the first and second mitoses, and four in the third, and suggests that a brachymeiotic reduction takes place. According to the interpretations of Dangeard and Winge fertiHzation does not take place in the oogonium of Sphaerotheca Hitmuli. For them the degenerating mass in the antheridium includes the male nucleus which thus degenerates in situ and the two nuclei seen lying side by side in the female organ represent the product of a premature division (fig. 42). Agai Stock Photo

RMRDTP5H–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 86 PLECTOMYCETES [CH. chromosomes is that of Winge who describes eight in the first and second mitoses, and four in the third, and suggests that a brachymeiotic reduction takes place. According to the interpretations of Dangeard and Winge fertiHzation does not take place in the oogonium of Sphaerotheca Hitmuli. For them the degenerating mass in the antheridium includes the male nucleus which thus degenerates in situ and the two nuclei seen lying side by side in the female organ represent the product of a premature division (fig. 42). Agai

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. Fig. 95. Balsamia vulgaris Vitt.; after Tulasne.. Fig. 96. Balsamia vulgaris Vitt.; section through hymenium ; after Tulasne. Fig. 97. Tuber rti/um Pico ; general view of fertile region; after Tulasne.. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Gwynne-Vaughan, Helen Charlotte Isabella (Fraser) Dame, 1879-. Cambridge [Eng] University Press Stock Photo

RMRDTNH1–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. Fig. 95. Balsamia vulgaris Vitt.; after Tulasne.. Fig. 96. Balsamia vulgaris Vitt.; section through hymenium ; after Tulasne. Fig. 97. Tuber rti/um Pico ; general view of fertile region; after Tulasne.. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Gwynne-Vaughan, Helen Charlotte Isabella (Fraser) Dame, 1879-. Cambridge [Eng] University Press

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 126 DISCOMYCETES [CH. "In the beech forests," he says, "the trees are much diseased; on the rough excrescences grow vast numbers of yellow balls. They are of the colour of the yolk of an egg, and vary in size from that of a bullet to that of a small apple ; in shape they are globular, but a little produced towards the point of attachment. They grow both on the branches and stems in groups. When young they contain much fluid and are quite tasteless, but in their older and altered state they form a very essential article of f Stock Photo

RMRDTNMW–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 126 DISCOMYCETES [CH. "In the beech forests," he says, "the trees are much diseased; on the rough excrescences grow vast numbers of yellow balls. They are of the colour of the yolk of an egg, and vary in size from that of a bullet to that of a small apple ; in shape they are globular, but a little produced towards the point of attachment. They grow both on the branches and stems in groups. When young they contain much fluid and are quite tasteless, but in their older and altered state they form a very essential article of f

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. IV] PEZIZALES III attached antheridium if the latter developed at a distance. But branching might also be regarded as a secondary or vegetative development, appearing after normal fertilization had ceased to occur. The presence of pores in the transverse septa of the trichbgyne suggests that the function of that organ in relation to an antheridium has only recently been lost.. Fig. 67. Jlumai-ia^ranu/ata Qne.; YOvmga.rchica.rp, X3'2o; after Blackman and Fraser. The ascogenous hyphae contain many nuclei irregularly arranged. Asci are form Stock Photo

RMRDTP02–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. IV] PEZIZALES III attached antheridium if the latter developed at a distance. But branching might also be regarded as a secondary or vegetative development, appearing after normal fertilization had ceased to occur. The presence of pores in the transverse septa of the trichbgyne suggests that the function of that organ in relation to an antheridium has only recently been lost.. Fig. 67. Jlumai-ia^ranu/ata Qne.; YOvmga.rchica.rp, X3'2o; after Blackman and Fraser. The ascogenous hyphae contain many nuclei irregularly arranged. Asci are form

RMRDD70F–. Botany for agricultural students . Botany. Fig. 348. — A Bird's Nest Fungus, Nidularia. About natural size. organic matter in the ground. Tlie sporophore is at first globose, but the gleba soon breaks out of the peridium and is elevated to some distance above ground by an elongating stalk. The spore masses arc slimy and have the odor of carrion. Certain insects which dissemi- nate the spores are attracted by the odor. Smuts (Ustilaginales). — The Smuts are parasitic Basidiomycetes. In some Smuts, the mycelium, although evident only in local areas, traverses widely through the host, while in

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 156 PYRENOMYCETES [CH. In due course the archicarp becomes surrounded by a sheath of vegetative hyphae within which its growth is continued so that a mass of cells is pro- duced from which asci at last arise. In the meantime the sheath becomes differentiated into an outer coat of relatively large, brown-walled hyphae, and an inner layer of smaller cells which become narrow and elongated. As development proceeds a cavity appears within the perithecium, usually just above the ascogenous cells, and branches from the lining mycelium grow out Stock Photo

RMRDTNBG–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 156 PYRENOMYCETES [CH. In due course the archicarp becomes surrounded by a sheath of vegetative hyphae within which its growth is continued so that a mass of cells is pro- duced from which asci at last arise. In the meantime the sheath becomes differentiated into an outer coat of relatively large, brown-walled hyphae, and an inner layer of smaller cells which become narrow and elongated. As development proceeds a cavity appears within the perithecium, usually just above the ascogenous cells, and branches from the lining mycelium grow out

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. Fig. 133. Zodiovtyces vorticellaritis'XXiz.yA&x; 2itzx Thaxtev. Fig. 134. Ceratomyces rostra' tus Tliaxter; exogenous spermatia; after Tliaxter. ^ Wolfe, Ann. Bot. xviii, 1904. Yamanouchi, Bot. Gaz. Ixii, 1906.. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Gwynne-Vaughan, Helen Charlotte Isabella (Fraser) Dame, 1879-. Cambridge [Eng] University Press Stock Photo

RMRDX13W–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. Fig. 133. Zodiovtyces vorticellaritis'XXiz.yA&x; 2itzx Thaxtev. Fig. 134. Ceratomyces rostra' tus Tliaxter; exogenous spermatia; after Tliaxter. ^ Wolfe, Ann. Bot. xviii, 1904. Yamanouchi, Bot. Gaz. Ixii, 1906.. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Gwynne-Vaughan, Helen Charlotte Isabella (Fraser) Dame, 1879-. Cambridge [Eng] University Press

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. Ill] PLECTASCALES 75 nuclei have travelled in pairs to the asci, where they unite; but Kuyper, in M. Barkeri, reports fertilization in the female organ. After the fertilization stage the oogonium enlarges and gives rise to asco- genous hyphae while the an- theridium and trichogyne de- generate. Investing filaments grow up to form a sheath, the in ner layers of which consist of delicate, nutritive cells. These degenerate early, producing a mass of protoplasm amongst which the ascogenous hyphae ramify. From the penultimate cells of the latt Stock Photo

RMREXDAN–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. Ill] PLECTASCALES 75 nuclei have travelled in pairs to the asci, where they unite; but Kuyper, in M. Barkeri, reports fertilization in the female organ. After the fertilization stage the oogonium enlarges and gives rise to asco- genous hyphae while the an- theridium and trichogyne de- generate. Investing filaments grow up to form a sheath, the in ner layers of which consist of delicate, nutritive cells. These degenerate early, producing a mass of protoplasm amongst which the ascogenous hyphae ramify. From the penultimate cells of the latt

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. VIIl] UREDINALES 213 Moreau describes only two, but Harper and Holden found a larger number, which became crowded together arid more or less fused during the later stages of the first and also during the second division. InGymnosporangium clavariaeforme (fig. 190) the first division is initiated, as in Coleosporium, by a synaptic phase, after which a spireme is formed and breaks up into chromosomes. These pass on to the spindle but soon lose their individuality and travel in irregular masses to the poles. The development of the spindle ha Stock Photo

RMRDX0G2–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. VIIl] UREDINALES 213 Moreau describes only two, but Harper and Holden found a larger number, which became crowded together arid more or less fused during the later stages of the first and also during the second division. InGymnosporangium clavariaeforme (fig. 190) the first division is initiated, as in Coleosporium, by a synaptic phase, after which a spireme is formed and breaks up into chromosomes. These pass on to the spindle but soon lose their individuality and travel in irregular masses to the poles. The development of the spindle ha

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 102 PYRENOMYCETES [CH. Leptosphaeria includes some 500 species characterized by the papillate or conical ostiole, usually free from hairs. The majority are saprophytes on plant remains, some are parasites on land plants, and some on the Red Algae. L. Lemaneae occurs on the thalliis of various species oi Lemanea {?ig. 121). The mycelium consists of uninucleate cells and ramifies in the intercellular spaces of the host, sending branched haustoria into the cells. Here and there the hyphae are dilated (fig. 122 a, b), and in these regions sho Stock Photo

RMRDTN9R–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 102 PYRENOMYCETES [CH. Leptosphaeria includes some 500 species characterized by the papillate or conical ostiole, usually free from hairs. The majority are saprophytes on plant remains, some are parasites on land plants, and some on the Red Algae. L. Lemaneae occurs on the thalliis of various species oi Lemanea {?ig. 121). The mycelium consists of uninucleate cells and ramifies in the intercellular spaces of the host, sending branched haustoria into the cells. Here and there the hyphae are dilated (fig. 122 a, b), and in these regions sho

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. I/O PYRENOMYCETES [CH. of conidiophores, from which small oval conidia are abstricted. In Xylaria these form a white coating, in marked contrast to the older black portions of the stroma, where the perithecia are maturing, and justify the name candle-snuff fungus, applied to some of the commoner species. If, in either genus, the stroma be sectioned during the conidial stage, nests of small hyphae, similar to those in Poronia, will be found, and are the first indica- tions of the perithecia. Sometimes a stouter hypha with larger nuclei, pr Stock Photo

RMRDX15E–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. I/O PYRENOMYCETES [CH. of conidiophores, from which small oval conidia are abstricted. In Xylaria these form a white coating, in marked contrast to the older black portions of the stroma, where the perithecia are maturing, and justify the name candle-snuff fungus, applied to some of the commoner species. If, in either genus, the stroma be sectioned during the conidial stage, nests of small hyphae, similar to those in Poronia, will be found, and are the first indica- tions of the perithecia. Sometimes a stouter hypha with larger nuclei, pr

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 2l6 PROTOBASIDIOMYCETES [CH.. Fig. 196. Triphragmidium Ulmariae (Schum.) Link; primary uredosorus; condition intermediate between migra- tion and conjugation of fertile cell; after Olive. that Moreau found both processes (cell-fusion being considerably more common than migration) in the same caeoma in Phragmidium subcorticium. Since 1905 nuclear association by the fusion of fertile cells in pairs has been observed in a number of species, and seems, according to our present knowledge, to be the usual method. In the primary uredosorus of Tr Stock Photo

RMRDX0EF–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 2l6 PROTOBASIDIOMYCETES [CH.. Fig. 196. Triphragmidium Ulmariae (Schum.) Link; primary uredosorus; condition intermediate between migra- tion and conjugation of fertile cell; after Olive. that Moreau found both processes (cell-fusion being considerably more common than migration) in the same caeoma in Phragmidium subcorticium. Since 1905 nuclear association by the fusion of fertile cells in pairs has been observed in a number of species, and seems, according to our present knowledge, to be the usual method. In the primary uredosorus of Tr

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 82 PLECTOMYCETES [CH.. Fig. 39. Erysiphe Polygoni; young perithecium containing uninucleate asci; after Harper. which undergo a change apparently analogous to lignification. nPhyllactinia the outermost layer, from which the secondary mycelium and the character- istic appendages are derived, consists of thin-walled cells, but in other genera it is not differentiated from the pro- tective zone. A single asciis or several may be formed in the peri- thecium ; the ascospores, numbering two to eight in each ascus, begin to develop during the s Stock Photo

RMRDTP6D–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 82 PLECTOMYCETES [CH.. Fig. 39. Erysiphe Polygoni; young perithecium containing uninucleate asci; after Harper. which undergo a change apparently analogous to lignification. nPhyllactinia the outermost layer, from which the secondary mycelium and the character- istic appendages are derived, consists of thin-walled cells, but in other genera it is not differentiated from the pro- tective zone. A single asciis or several may be formed in the peri- thecium ; the ascospores, numbering two to eight in each ascus, begin to develop during the s

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. Fig. 169. Gymnosporan^tt-m clavariaefornie Rees; development of spermatia, x 1185; after Blackman. simpler forms, such as Phragmidium, the spermogonium is indefinite in extent, and consists of spermatial hyphae arranged beneath the cuticle, which is perforated in the centre of the mass to form an ostiole. No regular para- physes are produced but a few spermatial hyphae may elongate and project as sterile threads (fig. 168 a). The spermatial hypha is a long, narrow cell with a central elongated nucleus. It is furnished at its free end with Stock Photo

RMRDX0PE–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. Fig. 169. Gymnosporan^tt-m clavariaefornie Rees; development of spermatia, x 1185; after Blackman. simpler forms, such as Phragmidium, the spermogonium is indefinite in extent, and consists of spermatial hyphae arranged beneath the cuticle, which is perforated in the centre of the mass to form an ostiole. No regular para- physes are produced but a few spermatial hyphae may elongate and project as sterile threads (fig. 168 a). The spermatial hypha is a long, narrow cell with a central elongated nucleus. It is furnished at its free end with

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 142 PYRENOMYCETES [CH. Lachnea cretea and the Ascoboli, where the coiled and septate archicarp. is often still functional. A very common initial organ in forms with embedded perithecia is the short filament of cells sometimes known as Woronin's hypha (fig. 103). The cells are large and contain well-marked nuclei and lie in a nest of small- celled vegetative mycelium. Woronin's hypha has been found among the Hypocreales mNectria and among the Sphaeriales in Xylaria and Hypoxylon; it remains to be shown whether it still functions. It may ha Stock Photo

RMRDTNE7–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 142 PYRENOMYCETES [CH. Lachnea cretea and the Ascoboli, where the coiled and septate archicarp. is often still functional. A very common initial organ in forms with embedded perithecia is the short filament of cells sometimes known as Woronin's hypha (fig. 103). The cells are large and contain well-marked nuclei and lie in a nest of small- celled vegetative mycelium. Woronin's hypha has been found among the Hypocreales mNectria and among the Sphaeriales in Xylaria and Hypoxylon; it remains to be shown whether it still functions. It may ha

. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. Fig. 149. Ustilago antheraritm Fr.; a. and b. conju- gating basidiospores; c. conjugation between a cell of the basidium and a basidiospore; after Harper. the other, but does not fuse with its nucleus (fig. 150). Later both nuclei divide, and a mycelium of binucleate cells is produced. It is on this mycelium that the infection of the host depends ; it penetrates the tissues usually of the seedling, but sometimes of the developing parts of the mature plant, being in most cases derived from spores which adhered to the seed coat. These may b Stock Photo

RMRDX0Y0–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. Fig. 149. Ustilago antheraritm Fr.; a. and b. conju- gating basidiospores; c. conjugation between a cell of the basidium and a basidiospore; after Harper. the other, but does not fuse with its nucleus (fig. 150). Later both nuclei divide, and a mycelium of binucleate cells is produced. It is on this mycelium that the infection of the host depends ; it penetrates the tissues usually of the seedling, but sometimes of the developing parts of the mature plant, being in most cases derived from spores which adhered to the seed coat. These may b

RMRDX0G9–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. Fig. 186. Endofhyllum Setnpervivi'L&v.; spores giving rise to basidia; both after Hoffmann. (fig. 186); its two nuclei fuse (fig. 187), its contents are extruded as a pro- mycelium, two successive nuclear divisions occur, cross walls appear and four basidiospores are produced, which, in due course, give rise to a uninucleate mycelium. The sporophytic stage thus endures only from the fusion of the fertile cells until the germination of the spores which they produce. Incidentally these observations in the case of Kunkelia nitens have de

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