Two centipedes hi-res stock photography and images

Two Scorpions and Two Centipedes, unknown artist, undated, Watercolor and gouache with pen and black ink and pen and brown ink on moderately thick, slightly textured, cream wove paper, Sheet: 15 × 10 3/4 inches (38.1 × 27.3 cm), animal art, Arachnida (class), Arthropoda (phylum Stock Photo

RM2DHWC2H–Two Scorpions and Two Centipedes, unknown artist, undated, Watercolor and gouache with pen and black ink and pen and brown ink on moderately thick, slightly textured, cream wove paper, Sheet: 15 × 10 3/4 inches (38.1 × 27.3 cm), animal art, Arachnida (class), Arthropoda (phylum

Orange and black centipede. A large banded orange and black centipede. Like all other centipedes, this kind has two poison fangs Stock Photo

RFH6BM23–Orange and black centipede. A large banded orange and black centipede. Like all other centipedes, this kind has two poison fangs

unknown artist, Two Scorpions and Two Centipedes, undated. Watercolor and gouache with pen and black ink and pen and brown ink on moderately thick, slightly textured, cream wove paper. animal art , Arachnida (class) , Arthropoda (phylum) Stock Photo

RM2E432EC–unknown artist, Two Scorpions and Two Centipedes, undated. Watercolor and gouache with pen and black ink and pen and brown ink on moderately thick, slightly textured, cream wove paper. animal art , Arachnida (class) , Arthropoda (phylum)

Two centipedes, illustration, vector on a white background. Stock Vector

RF2K4P0WY–Two centipedes, illustration, vector on a white background.

RMB25KTP–Centipedes

RMG4FGXK–ZOO Centipedes

Millipedes are similar to centipedes, but have two pairs of legs per body segment. Stock Photo

RF2BHDY3Y–Millipedes are similar to centipedes, but have two pairs of legs per body segment.

Group of arthropods, characterised by two pairs of jointed legs on most body segments; scientifically known as the class Diplopoda, vintage line drawi Stock Vector

RF2B7709F–Group of arthropods, characterised by two pairs of jointed legs on most body segments; scientifically known as the class Diplopoda, vintage line drawi

Millipedes are a group of arthropods that are characterised by having two pairs of jointed legs on most body segments. Stock Photo

RF2A3WDND–Millipedes are a group of arthropods that are characterised by having two pairs of jointed legs on most body segments.

Guide to the Crustacea, Arachnida, Onychophora and Myriopoda exhibited in the Department of Zoology, British Museum (Natural History) .. . gest andcommonest of the tropical Africanspecies of centipedes, and it isalso met with less frequently inthe more temperate parts of Africa.Several of the species belongingto this order are very widely dis-tributed, and two of them (Scolo-pendra morsitans and -S. suhspi-uipea), have been introduced, likethe common rat or cockroach, intomost of the seaport towns of theworld, but, unlike these animals,they are unable to maintain them-selves as far north as En Stock Photo

RM2AKNAJ8–Guide to the Crustacea, Arachnida, Onychophora and Myriopoda exhibited in the Department of Zoology, British Museum (Natural History) .. . gest andcommonest of the tropical Africanspecies of centipedes, and it isalso met with less frequently inthe more temperate parts of Africa.Several of the species belongingto this order are very widely dis-tributed, and two of them (Scolo-pendra morsitans and -S. suhspi-uipea), have been introduced, likethe common rat or cockroach, intomost of the seaport towns of theworld, but, unlike these animals,they are unable to maintain them-selves as far north as En

Southern girdled scolopendra (Scolopendra cingulata), cut-out, Greece, Peloponnese Stock Photo

RMFJ58PW–Southern girdled scolopendra (Scolopendra cingulata), cut-out, Greece, Peloponnese

Centipede crawling along the sidewalk in Costa Rica Stock Photo

RFD3K11D–Centipede crawling along the sidewalk in Costa Rica

The National Museum of Anthropology,Mexico city,Mexico A pot found at Los Otates ,Veracruz Stock Photo

RMECR8KY–The National Museum of Anthropology,Mexico city,Mexico A pot found at Los Otates ,Veracruz

. A manual for the study of insects. Insects. 46 THE STUDY OF INSECTS. classed among our friends. And all of them are of interest to the naturahst as representatives of a distinct type of Arthropods. If we omit certain small and rather uncommon forms, the Myriapods may be classed in two orders ; one consisting of the Centipedes, the other of the Millipedes. Order Chilopoda (Chi-lop'o-da). The Centipedes, The centipedes can be recognized at a glance by the fact that each segment of the body bears a single pair of legs (Fig. 55). The body is usually flattened, and the antennae are long and many- Stock Photo

RMPFW7GY–. A manual for the study of insects. Insects. 46 THE STUDY OF INSECTS. classed among our friends. And all of them are of interest to the naturahst as representatives of a distinct type of Arthropods. If we omit certain small and rather uncommon forms, the Myriapods may be classed in two orders ; one consisting of the Centipedes, the other of the Millipedes. Order Chilopoda (Chi-lop'o-da). The Centipedes, The centipedes can be recognized at a glance by the fact that each segment of the body bears a single pair of legs (Fig. 55). The body is usually flattened, and the antennae are long and many-

Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 '^'^^^M^M^ Fig. 68.—Isotoma. Two-layered stage, (gc) Gorm cells, (il) Inner layer, (yc) Yolk cells. dc '^^M^^mk^^S^^ji Fig. 69.—Isotoma. Anlage of dorsal organ (dc). (ect) Ectoderm. Stock Photo

RMRWRACF–Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 '^'^^^M^M^ Fig. 68.—Isotoma. Two-layered stage, (gc) Gorm cells, (il) Inner layer, (yc) Yolk cells. dc '^^M^^mk^^S^^ji Fig. 69.—Isotoma. Anlage of dorsal organ (dc). (ect) Ectoderm.

RMGWNABG–TWO MEERKATS EATING

RF2BHDY5F–Millipedes are similar to centipedes, but have two pairs of legs per body segment.

. The boy travellers in Australasia : adventures of two youths in a journey to the Sandwich, Marquesas, Society, Samoan and Feejee islands, and through the colonies of New Zealand, New South Wales, Queensland, Victoria, Tasmania, and South Australia. o means uncommon. In some localities one mightgo about for years without seeing a snake, while in others the deadlyreptiles are so numerous that caution must be exercised. The worstregions are said to be the cane - fields of the Mackay district and thereed-beds on the Murray Kiver. There are centipedes and scorpions in Australia whose bite is poi- Stock Photo

RM2AFJD1D–. The boy travellers in Australasia : adventures of two youths in a journey to the Sandwich, Marquesas, Society, Samoan and Feejee islands, and through the colonies of New Zealand, New South Wales, Queensland, Victoria, Tasmania, and South Australia. o means uncommon. In some localities one mightgo about for years without seeing a snake, while in others the deadlyreptiles are so numerous that caution must be exercised. The worstregions are said to be the cane - fields of the Mackay district and thereed-beds on the Murray Kiver. There are centipedes and scorpions in Australia whose bite is poi-

Centipede close up on sidewalk in Costa Rica (Scutigeromorph) Stock Photo

RFD3K68H–Centipede close up on sidewalk in Costa Rica (Scutigeromorph)

. Agricultural zoology. Zoology. SCORPIONS, SPIDERS, MITES. 195 GLASS II.: MYRIOPODA (CENTIPEDES AND MILLIPEDES). Respiration by tracheae, as in insects. The body consists of a head and a large number of very similar segments, each of which possesses limbs. One pair of antennse. This class is divided into two orders: (1) that of Centipedes (Ghilopoda), with mouth-parts adapted for seizing prey, and one pair of legs to each segment; (2) that of Millipedes (Chilog- natha), adapted for de- vouring substances re- sembling humus, also the parts of plants; and two pairs of legs to each segment. Here Stock Photo

RMPG0F4F–. Agricultural zoology. Zoology. SCORPIONS, SPIDERS, MITES. 195 GLASS II.: MYRIOPODA (CENTIPEDES AND MILLIPEDES). Respiration by tracheae, as in insects. The body consists of a head and a large number of very similar segments, each of which possesses limbs. One pair of antennse. This class is divided into two orders: (1) that of Centipedes (Ghilopoda), with mouth-parts adapted for seizing prey, and one pair of legs to each segment; (2) that of Millipedes (Chilog- natha), adapted for de- vouring substances re- sembling humus, also the parts of plants; and two pairs of legs to each segment. Here

RMRWTYDR–Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 366 EMBRYOLOGY OF INSECTS AND MYRIAPODS The entoderm that will form the epithelial lining of the mid-gut will develop from two masses of cells, which form the two ends of the inner layer. These are not connected by a middle entodermal strand. The remainder of the inner layer lying between the entodermal masses will become the mesoderm. This is similar to the development of the entoderm

RMH05C1H–TWO MEERKATS LOOKING OUT

RF2BHDY50–Millipedes are similar to centipedes, but have two pairs of legs per body segment.

The maid of Redenfayn, an allegory of two worlds, in three books: I The book of loves and dreams . t The Maid of Redcnfayn. Huge scorpions, vampires and lizards vile,Tarantulas, great wasps and centipedes.Serpents and hornets, chigres, fleas and lice,Base murderers, and birds and beasts of prey.And all the vermin of the land or seaThat live on blood, or mar the peace of men;—Thus showing that, while Satan loved their deeds,Their treason praised, their names immortalized.Them he despised as traitors to their race.Some treason love, but traitors all despise.Odious the birds that their own nests Stock Photo

RM2AJFC6A–The maid of Redenfayn, an allegory of two worlds, in three books: I The book of loves and dreams . t The Maid of Redcnfayn. Huge scorpions, vampires and lizards vile,Tarantulas, great wasps and centipedes.Serpents and hornets, chigres, fleas and lice,Base murderers, and birds and beasts of prey.And all the vermin of the land or seaThat live on blood, or mar the peace of men;—Thus showing that, while Satan loved their deeds,Their treason praised, their names immortalized.Them he despised as traitors to their race.Some treason love, but traitors all despise.Odious the birds that their own nests

. Our search for a wilderness; an account of two ornithological expeditions to Venezuela and to British Guiana. Natural history; Birds. THE LAKE OF ITTCH. 39 we were troubled scarcely at all with noxious insects. "Jig- gers" there were in moderate numbers but one could "col- lect" more in one day in Virginia than in a month here at this season. During our entire stay we saw only about three or four minute ticks, while mosquitoes were absent, except at night. If we dug in rotten logs, we were sure to unearth centipedes and scorpions, many of them, — but otherwise we. Fig. 19 Stock Photo

RMPFYJJ1–. Our search for a wilderness; an account of two ornithological expeditions to Venezuela and to British Guiana. Natural history; Birds. THE LAKE OF ITTCH. 39 we were troubled scarcely at all with noxious insects. "Jig- gers" there were in moderate numbers but one could "col- lect" more in one day in Virginia than in a month here at this season. During our entire stay we saw only about three or four minute ticks, while mosquitoes were absent, except at night. If we dug in rotten logs, we were sure to unearth centipedes and scorpions, many of them, — but otherwise we. Fig. 19

RMRWW530–Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 278 EMBRYOLOGY OF INSECTS AND MYRIAPODS with the developing proctodaeum (Fig. 211, mge), develops into the posterior mesenteron rudiment. As with the anterior mesenteron rudi- ment, two ribbons of cells, here anteriorly directed, grow out from the posterior rudiment and, fusing with the anterior ribbons, later spread around the yolk to form the mid-gut epithelium. In the main, the obser

TWO MEERKATS HELPING THE WATCH Stock Photo

RMGW5WYA–TWO MEERKATS HELPING THE WATCH

RF2BHDY4E–Millipedes are similar to centipedes, but have two pairs of legs per body segment.

The entomologist's text book : an introduction to the natural history, structure, physiology and classification of insects, including the Crustacea and Arachnida . figured a species eighteen incheslong, and three quarters of an inch broad. In Europe, however,few species exceed two or three inches in length. These insects, unhke the Jididce, ruu very quickly; according to CENTIPEDES. 155 M. Veiss, quoted by Griffith, the Scolopendra forcipata (belongingto Dr. Leachs genus Lithobius), when walking, successively movesits numerous legs, one portion of which are brought in contact withthe line of p Stock Photo

RM2AKMJ7F–The entomologist's text book : an introduction to the natural history, structure, physiology and classification of insects, including the Crustacea and Arachnida . figured a species eighteen incheslong, and three quarters of an inch broad. In Europe, however,few species exceed two or three inches in length. These insects, unhke the Jididce, ruu very quickly; according to CENTIPEDES. 155 M. Veiss, quoted by Griffith, the Scolopendra forcipata (belongingto Dr. Leachs genus Lithobius), when walking, successively movesits numerous legs, one portion of which are brought in contact withthe line of p

RMRWTY61–Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 364 EMBRYOLOGY OF INSECTS AND MYRIAPODS While the inner layer, which is to be described later, is forming, the embryo lengthens rapidly. The head end reaches the anterior pole of the egg at the twentieth hour and extends to the dorsal side where it develops into two hollow lobes. The posterior extremity in the mean- time pushes under the germ cells and grows into a spiral around the ger

RMGWNACE–TWO MEERKAT'S ON LOOKOUT

Zöology; a textbook for colleges and universities . FIG. 78. Two millipedes. tic. 79. Dorsal and ventral views ofa common centipede. 266 ZOOLOGY Centipedes TheSymphyla ThePauropoda Class Chilopoda The centipedes are so called because they are supposedto have a hundred legs, though the number differs, indifferent forms, from thirty to over three hundred. Theydiffer from the diplopods in having only one pair of legsto a segment, and by the greater number of joints to theantennae. In the diplopods the antennae do not havemore than seven joints, in the chilopods they have atleast twelve. Some cent Stock Photo

RM2ANJ8PA–Zöology; a textbook for colleges and universities . FIG. 78. Two millipedes. tic. 79. Dorsal and ventral views ofa common centipede. 266 ZOOLOGY Centipedes TheSymphyla ThePauropoda Class Chilopoda The centipedes are so called because they are supposedto have a hundred legs, though the number differs, indifferent forms, from thirty to over three hundred. Theydiffer from the diplopods in having only one pair of legsto a segment, and by the greater number of joints to theantennae. In the diplopods the antennae do not havemore than seven joints, in the chilopods they have atleast twelve. Some cent

RMRWW4H9–Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 OLIGONEPHRIDIA 275 is retained until after blastokinesis, when the embryo comes again to the surface and the yolk lies in the developing mid-gut lumen. The formation of the two layers of the germ band does not take place simultaneously; nevertheless, it is to be regarded as a single step in the development of the embryo. The outer layer constitutes the ectoderm; the inner one, the meso-

RMGWNACW–TWO MEERKAT'S ON LOOKOUT

RM2AFJEAF–. The boy travellers in Australasia : adventures of two youths in a journey to the Sandwich, Marquesas, Society, Samoan and Feejee islands, and through the colonies of New Zealand, New South Wales, Queensland, Victoria, Tasmania, and South Australia. APTER XYI. RIDING THROtlGH THE BUSH.—AUSTRALIAN HOSPITALITY.—ARRIVAL AT THE STA-TION.—THE BUILDINGS AND THEIR SURROUNDINGS.— A SNAKE IX FREDSBED.—SNAKES IN AUSTRALIA.—UNDERWOODS REMEDY FOR SNAKE-BITES, ANDWHAT CAME OF IT.—CENTIPEDES AND SCORPIONS.—A VENOMOUS SPIDER.—NOC-TURNAL NOISES AT A CATTLE-STATION.—HORSES AND THEIR TRAITS.—BUCK-JUMPING AND R

RMRWT6RM–Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 OLIGOENTOMATA AND APTILOTA 183 The periplasm is exceedingly thin. By the time there are 64 cleavage nuclei, each in an island of cytoplasm, they reach the surface where the nuclei continue to divide to form the blastoderm. At this stage no nuclei remain behind in the yolk. At one side of the egg a small circular area is formed where the blastoderm is thicker and provided with two Fig

RMGWNAD5–TWO MEERKAT'S ON LOOKOUT

. Sanitary entomology; the entomology of disease, hygiene and sanitation. has been carefully studied by Cornwall, is on the dorsal surface of theclaw a little way from the apex and somewhat near the external side.There is one venom gland in each of two venom claws. This species isnocturnal in habit and is not naturally vicious and will not bite unlesshurt or worried. A centipedes bite may be merely a snap, but once he findshis fangs sink into the fine tissues his main idea, if other portions of himare not being mistreated, seems to be to eat. To this end he digs as manylegs as he can apply int Stock Photo

RM2AG0R5N–. Sanitary entomology; the entomology of disease, hygiene and sanitation. has been carefully studied by Cornwall, is on the dorsal surface of theclaw a little way from the apex and somewhat near the external side.There is one venom gland in each of two venom claws. This species isnocturnal in habit and is not naturally vicious and will not bite unlesshurt or worried. A centipedes bite may be merely a snap, but once he findshis fangs sink into the fine tissues his main idea, if other portions of himare not being mistreated, seems to be to eat. To this end he digs as manylegs as he can apply int

RMRWT98G–Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 236 EMBRYOLOGY OF INSECTS AND MYRIAPODS it arises from the lateral edges of the germ band as two flaps which spread medially toward each other and ultimately fuse into a single membrane. It is said to be of ectodermic origin. This membrane at first serves as a gliding surface beneath which the splanchnic mesoderm progresses medially. At first in close contact with each other, later the

RMH05C29–TWO MEERKATS LOOKING OUT

First lesson in zoology : adapted for use in schools . ^K Til.vS?*S if^™^ tpUwwuw. wm 1.^. Fio. 97.-Extemal anatomy of Caloptenus spretus, the.headand thorax disjointed. (To face page 91.) CHAPTER XII.MILLEPEDES AND CENTIPEDES.* The millepedes and centipedes are examples of the classMyriopoda, so called from tlie numerous feet they possess.If we examine a common millepede, called Julus, whichmay be found under sticks and dead leaves in damp places,its body will be seen to consist of a head with short anten-nae succeeded by a large number of cylindrical segments,each bearing two pairs of feet, Stock Photo

RM2AKWYGJ–First lesson in zoology : adapted for use in schools . ^K Til.vS?*S if^™^ tpUwwuw. wm 1.^. Fio. 97.-Extemal anatomy of Caloptenus spretus, the.headand thorax disjointed. (To face page 91.) CHAPTER XII.MILLEPEDES AND CENTIPEDES.* The millepedes and centipedes are examples of the classMyriopoda, so called from tlie numerous feet they possess.If we examine a common millepede, called Julus, whichmay be found under sticks and dead leaves in damp places,its body will be seen to consist of a head with short anten-nae succeeded by a large number of cylindrical segments,each bearing two pairs of feet,

RMRWR92K–Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 272 EMBRYOLOGY OF INSECTS AND MYRIAPODS dorsoventral flattened sack, one wall of which is the embryo, the other the amnion. At first the amnion and the embryo show a similar cell structure except at the posterior end at the point of invagination. There the amniotic cavity runs out into two furrows (Fig. 202), the inner wall of the invagination representing the prolongation of the amnion

TWO MEERKAT'S ON THE LOOKOUT Stock Photo

RMGYFYT1–TWO MEERKAT'S ON THE LOOKOUT

The maid of Redenfayn, an allegory of two worlds, in three books: I The book of loves and dreams . The Maid of Redciifayn. No dangers lurk here near ones daily path, No deadly snakes hide in the lofty grass, No spiders, centipedes nor scorpions, No pitfalls, traps nor snares nor stumbling-blocks No witches, goblins, ghosts nor bugaboos, No deaths, no coffins, graves nor funerals. No cobwebs here, dirt, mud nor carrion; Nought to offend the eye, ear, smell or taste, Nought to befoul, or taint, or make unclean; No flaws nor cracks, specks, blots nor blemishes; No moths nor worms, no bugs nor mic Stock Photo

RM2AJEJT9–The maid of Redenfayn, an allegory of two worlds, in three books: I The book of loves and dreams . The Maid of Redciifayn. No dangers lurk here near ones daily path, No deadly snakes hide in the lofty grass, No spiders, centipedes nor scorpions, No pitfalls, traps nor snares nor stumbling-blocks No witches, goblins, ghosts nor bugaboos, No deaths, no coffins, graves nor funerals. No cobwebs here, dirt, mud nor carrion; Nought to offend the eye, ear, smell or taste, Nought to befoul, or taint, or make unclean; No flaws nor cracks, specks, blots nor blemishes; No moths nor worms, no bugs nor mic

RMRWWC06–Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 346 EMBRYOLOGY OF INSECTS AND MYRIAPODS and conspicuous, extending from the first gnathal head segment to the last abdominal segment. On each side of the neural groove the neuro- blasts are already distinct in each segment. Of these there are from two to four pairs in transverse section of the intermediate body segments (Fig. 304^), though they are not so regularly arranged as described

. An introduction to zoology : for the use of high schools . pair of legsend in powerful claws perforated by the ductof a poison-gland, and are turned forwards tosupplement the three paiis of jaws. In theChilognatha, on the other hand, there is onlyone pair of maxillee below the mandibles, andthey are united to form a labium. The twoFig. 145.-Scutigera. groups further difier in that the Centipedeshave only one pair of legs to each segment, the Millipedes two iand that, while the Centipedes resemble the insects in theposition of the opening of the oviduct, this is near the head inthe Millij^ted Stock Photo

RM2CDEEKX–. An introduction to zoology : for the use of high schools . pair of legsend in powerful claws perforated by the ductof a poison-gland, and are turned forwards tosupplement the three paiis of jaws. In theChilognatha, on the other hand, there is onlyone pair of maxillee below the mandibles, andthey are united to form a labium. The twoFig. 145.-Scutigera. groups further difier in that the Centipedeshave only one pair of legs to each segment, the Millipedes two iand that, while the Centipedes resemble the insects in theposition of the opening of the oviduct, this is near the head inthe Millij^ted

RMRWMNRN–Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 4 EMBRYOLCXiY OF INSECTS AND MYRIAPODS Cell Division.—Cells multiply by direct, or indirect division. By direct division (amitosis) the cell including the nucleus is merely pinched in two. This process is characteristic of aging cells. Indirect division (mitosis), the usual method of nuclear division, is a series of complex processes which may be arranged in several phases (Fig. 2). In

. The study of animal life . w internal organs such as a heart ; the whole bodyis better knit together. A crayfish may part with his claw andgrow another in its place, but the animal will not survive being cutin two as some kinds of Annelids do. The series includes at least five classes :— Crustacea, almost all aquatic, and breathing by gills. Protracheata, represented by the genus Feripatus. Myriapoda, centipedes and millipedes. Insecta, more or less aerial. Arachnida, spiders, scorpions, mites, etc CHAP. XV Backboneless Atiimah 239 The members of the last four classes usually breathe by mean Stock Photo

RM2CE1MWW–. The study of animal life . w internal organs such as a heart ; the whole bodyis better knit together. A crayfish may part with his claw andgrow another in its place, but the animal will not survive being cutin two as some kinds of Annelids do. The series includes at least five classes :— Crustacea, almost all aquatic, and breathing by gills. Protracheata, represented by the genus Feripatus. Myriapoda, centipedes and millipedes. Insecta, more or less aerial. Arachnida, spiders, scorpions, mites, etc CHAP. XV Backboneless Atiimah 239 The members of the last four classes usually breathe by mean

RMRWWEE3–Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 A B Fig. 335.—Calliphora vomitoria. Section A is taken at the level of k of Fig. 329; B at the level of u. (ect) Ectoderm, {ent) Entoderm, {mes) Mesoderm. Posteriorly at this time the posterior mesenteron rudiment is divided api- cally into two branches in the same manner as the anterior rudiment. With the shortening of the embryo the proctodaeal opening comes to lie near the posterior

. Sharp eyes; a rambler's calendar of fifty-two weeks among insects, birds and flowers; . r wood-frog, or arare cocoon, to say nothing of all the host of squirmingthings—beetles, bugs, caterpillars, centipedes, iules, ar-madillo-bugs, and ants—which are among the certaindwellers beneath almost any stone in the field. Sur-prise after surprise cameto me, until at last I^^ thought I had them all. ^f But one day I found out my mistake. I had lifted a largeflat rock and turned itover, when I was im-mediately saluted witha distinct explosion, ac-companied with a tinycloud of smoke amongthe border gr Stock Photo

RM2CPDB8H–. Sharp eyes; a rambler's calendar of fifty-two weeks among insects, birds and flowers; . r wood-frog, or arare cocoon, to say nothing of all the host of squirmingthings—beetles, bugs, caterpillars, centipedes, iules, ar-madillo-bugs, and ants—which are among the certaindwellers beneath almost any stone in the field. Sur-prise after surprise cameto me, until at last I^^ thought I had them all. ^f But one day I found out my mistake. I had lifted a largeflat rock and turned itover, when I was im-mediately saluted witha distinct explosion, ac-companied with a tinycloud of smoke amongthe border gr

RMRWMTDP–Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 A TYPE OF EMBRYONIC DEVELOPMENT IN INSECTS 15 Gradually appendages appear on the segments, the antennae arising pos- torally but later migrating forward. In front of the stomodaeal opening which has formed in the first segment is the labrum. The hypopharynx which develops from the fusion of two small elevations near the median line behind the stomodaeum belongs to the intercalary segmen

. Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching. Embryology -- Insects; Embryology -- Myriapoda. 410 EMBRYOLOGY OF INSECTS AND MYRIAPODS the molt at the beginning of the second postembryonic developmental period. Consequently the two pairs of ganglia by the constriction of the necks of the depression lose their connection with the ectoderm of the future body wall. The nerve connection between antennae and deutocerebrum is early established. Pflugfelder (1932) states that he made no observations on the Stock Photo

RMREYFNT–. Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching. Embryology -- Insects; Embryology -- Myriapoda. 410 EMBRYOLOGY OF INSECTS AND MYRIAPODS the molt at the beginning of the second postembryonic developmental period. Consequently the two pairs of ganglia by the constriction of the necks of the depression lose their connection with the ectoderm of the future body wall. The nerve connection between antennae and deutocerebrum is early established. Pflugfelder (1932) states that he made no observations on the

RMRWRAYY–Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 Fig. 75.—Isotoma. Dorsal organ, ser) Amnioserosa. {cut) Crenated membrane. possibly be concerned with the molting of the crenated membranes. Buds of head and thoracic appendages are now evident as well as the anterior abdominal segments (Figs. 76, 77). A section through the region of an appendage now reveals that the inner layer consists of two layers laterally and of one layer in the m

RMREYJCN–. Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching. Embryology -- Insects; Embryology -- Myriapoda. 236 EMBRYOLOGY OF INSECTS AND MYRIAPODS it arises from the lateral edges of the germ band as two flaps which spread medially toward each other and ultimately fuse into a single membrane. It is said to be of ectodermic origin. This membrane at first serves as a gliding surface beneath which the splanchnic mesoderm progresses medially. At first in close contact with each other, later the membrane and the meso

RMRWWEDY–Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 SIPHONAPTERA AND DIPT ERA 379 The rudiment by this time has become cleft at the free end into two branches which are in contact with a ribbon of mesoderm that is destined to form the muscle layers of the mid-gut. Later the mesenteron rudi- ments elongate, and the stomodaeal invagination deepens (Fig. 332.4). A B Fig. 335.—Calliphora vomitoria. Section A is taken at the level of k of

RMRF096Y–. Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching. Embryology -- Insects; Embryology -- Myriapoda. SIPHONAPTERA AND DIPTERA 369 about two hours before the edges of the ectoderm grow together and fuse along the dorsal mid-longitudinal line. At 56 hours outgrowths that are the first evidence of the developing Malpighian tubules appear at the end of the proctodaeum. They develop into elongate slender tubules that can be seen distinctly in the later stages of the embryo. About 10 hours later the proctodaeum

RMRWRM3R–Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 ORTHOPTEROIDEA (PANORTHOPTERA) 231 smaller dorsoanal pouch (Fig. 152), the ventral pouch completely fining the antenna. The dorsorostral portions of the two coelomic sacs, shortly before blastokinesis, approach each other; their median walls fuse and thus form the anterior portion of the cephalic aorta which func- tions as a blood-distributing apparatus. The median walls of the dorso- a

. Text-book of zoology for schools and colleges. Zoology. ANARTHROPODA. 119 toward that side of tte body upon which the nervous system is situated, (See also the transverse section of an Annulose animal, Fig. 1.) The entire sub-kingdom of the Annulosa is divided into two great divisions termed Arthropoda and Anarthropoda, according as the body is provided with jointed appendages or not. In the Arthropoda, in which the body- rings are furnished (some or all) with jointed appendages, are included the Crustaceans (lobsters, crabs, etc.), the spiders and scorpions, the centipedes, and the insects. Stock Photo

RMRE0G17–. Text-book of zoology for schools and colleges. Zoology. ANARTHROPODA. 119 toward that side of tte body upon which the nervous system is situated, (See also the transverse section of an Annulose animal, Fig. 1.) The entire sub-kingdom of the Annulosa is divided into two great divisions termed Arthropoda and Anarthropoda, according as the body is provided with jointed appendages or not. In the Arthropoda, in which the body- rings are furnished (some or all) with jointed appendages, are included the Crustaceans (lobsters, crabs, etc.), the spiders and scorpions, the centipedes, and the insects.

RMRWWE5K–Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 376 EMBRYOLOGY OF INSECTS AND MYRIAPODS The mesodermal tube continues to elongate, its caudal end being drawn more and more into the interior, thus becoming more and more angulated until at the time when the tube is at its maximum length the two limbs of the tube lie parallel with each other. Before the union of the mesenteron ribbons on the ventral side, clefts form laterally in the me

RMREYJAW–. Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching. Embryology -- Insects; Embryology -- Myriapoda. 272 EMBRYOLOGY OF INSECTS AND MYRIAPODS dorsoventral flattened sack, one wall of which is the embryo, the other the amnion. At first the amnion and the embryo show a similar cell structure except at the posterior end at the point of invagination. There the amniotic cavity runs out into two furrows (Fig. 202), the inner wall of the invagination representing the prolongation of the amnion, the outer wall the

RMRWTYM3–Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 368 EMBRYOLOGY OF INSECTS AND MYRIAPODS terior mesenteron ribbons that grow cephalad from the posterior enteron rudiment at the end of the proctodaeum is similar to the formation of the anterior pair already described. The two pairs of ribbons meet and fuse Fig. 324.âSciara. Cross section of 60-hour embryo. Differentiation of somatic (som. m) and splanchnic {splm) mesoderm, (ect) Ect

RMREYJAJ–. Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching. Embryology -- Insects; Embryology -- Myriapoda. OLIGONEPHRIDIA 275 is retained until after blastokinesis, when the embryo comes again to the surface and the yolk lies in the developing mid-gut lumen. The formation of the two layers of the germ band does not take place simultaneously; nevertheless, it is to be regarded as a single step in the development of the embryo. The outer layer constitutes the ectoderm; the inner one, the meso- and entoderm. The vi

RMRWWA2Y–Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 326 EMBRYOLOGY OF INSECTS AND MYRIAPODS The separation does not take place along the entire margin of the lateral plates simultaneously but occurs first at the cephalic end of the egg as a cap-like fold which grows rapidly caudad. A similar but slighter fold is later formed at the caudal end of the egg. The two folds eventually meet and coalesce near the caudal pole of the egg. At first

RMREYJAC–. Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching. Embryology -- Insects; Embryology -- Myriapoda. 278 EMBRYOLOGY OF INSECTS AND MYRIAPODS with the developing proctodaeum (Fig. 211, mge), develops into the posterior mesenteron rudiment. As with the anterior mesenteron rudi- ment, two ribbons of cells, here anteriorly directed, grow out from the posterior rudiment and, fusing with the anterior ribbons, later spread around the yolk to form the mid-gut epithelium. In the main, the observations of Karawaiew

RMRWT9PP–Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 240 EMBRYOLOGY OF INSECTS AND MYRIAPODS formed, the first pair arising after the formation of the provisional dorsal closure but before blastokinesis. The separation of the outer dorso- lateral end of the somatic mesoderm from the provisional dorsal closure gives rise to the two more or less spindle-shaped lateral sinuses. Later the first pair of lateral sinuses is lost by the breaking

RMRF097R–. Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching. Embryology -- Insects; Embryology -- Myriapoda. TRICHOPTERA AND LEPIDOPTERA 343 depth than elsewhere. At no time and at no part of the germ band is there the shghtest resemblance to the formation of a gastrular tube. Neither is there a proliferation at this time along the middle line, as described by Eastham for Pieris.. Fig. 301.—Diacrisia. Section through head at stomodaeum (stom). (am) Amnion. At 42 hours (Fig. 297C) the two anteriorly directed cephah

RMRWW789–Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 NEUROPTERA AND COLEOPTERA 295 brown. The yolk consists of globules of varying size which are sur- rounded by cytoplasm which, however, is not arranged as a reticulum at this time. The periplasm (Figs. 234, 235) surrounding the yolk in some cases seems to consist of two layers: an outer one which stains more lightly than the inner layer. At the posterior pole of the egg an irregular -M

RMREYJAH–. Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching. Embryology -- Insects; Embryology -- Myriapoda. 276 EMBRYOLOGY OF INSECTS AND MYRIAPODS ectoderm including the evaginations for the appendages. The coelomic sacs are here open toward the yolk. Later the yolk retracts from the germ band, leaving free an open space, the definitive body cavity as indicated in Fig. 208 of Ariasa tristis. The first differentiation of the inner layer on the margin of the body cavity consists of the segmentation of the two long

RMRWTYGW–Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 SIPHONAPTERA AND DIPTERA 367 At the fiftieth hour the cells lining the neural groove may be seen in cross section as two parallel vertical rows of neuroblasts formed in the neural ridge. They soon are modified as the ridge widens out and show the presence of ganglia before the sixty-fifth hour. The ganglia become distinct with the appearance of the neuropile. The ectoderm separates from

RMRF095J–. Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching. Embryology -- Insects; Embryology -- Myriapoda. 396 EMBRYOLOGY OF INSECTS AND MYRIAPODS 24 pairs of ganglia, the first belonging to the maxilliped segment, 21 to the rump segments, the last 2 to the pregenital and genital segments. The last two pairs of ganglia later fuse in one. Ganglia are not developed in the telson. The supra-esophageal ganglion, or brain, is here considered as com- posed of three parts: the forebrain, or procerebrum (or protocerebru

RMRWW6WE–Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 292 EMBRYOLOGY OF INSECTS AND MYRIAPODS The fragment of yolk that Ues in the periphery takes no further part in furnishing nutriment to the embryo; the one- or two- nucleated inner part, however, continues to function. The embryo as it lengthens rolls up (Fig. 228), the amnion stretching, becoming thinner and membranous in appearance, and finally fusing at the point of tangency whereby

RMREYJ9G–. Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching. Embryology -- Insects; Embryology -- Myriapoda. NEUROPTERA AND COLEOPTERA 295 brown. The yolk consists of globules of varying size which are sur- rounded by cytoplasm which, however, is not arranged as a reticulum at this time. The periplasm (Figs. 234, 235) surrounding the yolk in some cases seems to consist of two layers: an outer one which stains more lightly than the inner layer. At the posterior pole of the egg an irregular -M. Fig. 234.—Brachyrhinu

RMRWT6RN–Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 Fig. 102.—Campodea. Section of egg with entoderm cells (e?ii). irregular layers of nuclei (Fig. 100). From all parts of the surface, nuclei migrate toward the margin of the thicker area, with the result that the upper two-thirds of the blastoderm loses most of its nuclei and the lower third gains them (Fig. 101). Nuclei then leave the center of the thick- ened area and pile up on the si

RMRF0992–. Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching. Embryology -- Insects; Embryology -- Myriapoda. HYMENOPTERA 313 region. Unlike that of P. dryomyiae as described by Silvestri (1916), the first polar body does not divide during the second maturation. Between the tenth and twelfth hours the polar nucleus (the fused polar bodies) increases in size to become the "paranuclear mass" (Fig. 260C). Just before cleavage of the fusion nucleus the paranuclear mass divides amitotically to form two subequa

RMRWPD1C–Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 ECTODERMAL DERIVATIVES 105 divided into three pairs of lobes (Fig. 47, lob), the most lateral being the optic lobes (lob.l). In the two median pairs of lobes the neuroblasts (neur) have the typical form of those found in the ventral nerve cords, the daughter cells (gglc) forming the usual ganglion cells whose interlacing fibers represent the neuropile. The neuroblasts degenerate after t

RMRF0973–. Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching. Embryology -- Insects; Embryology -- Myriapoda. 366 EMBRYOLOGY OF INSECTS AND MYRIAPODS The entoderm that will form the epithelial lining of the mid-gut will develop from two masses of cells, which form the two ends of the inner layer. These are not connected by a middle entodermal strand. The remainder of the inner layer lying between the entodermal masses will become the mesoderm. This is similar to the development of the entoderm and mesoderm in Musca

RMRWW8YF–Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 318 EMBRYOLOGY OF INSECTS AND MYRIAPODS The second polar body (Bl) and the inner nucleus (A2) of the first polar body now fuse to form the polar nucleus, or the so-called 'paranucleus' (Fig. 267,7iu. p), the outer nucleus (Al) of the first polar body later under- going dissolution. That only two and not all three polar bodies enter into the formation of the polar nucleus (paranucleus) i

RMREYJCX–. Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching. Embryology -- Insects; Embryology -- Myriapoda. ORTHOPTEROIDEA (PANORTHOPTERA) 231 smaller dorsoanal pouch (Fig. 152), the ventral pouch completely fining the antenna. The dorsorostral portions of the two coelomic sacs, shortly before blastokinesis, approach each other; their median walls fuse and thus form the anterior portion of the cephalic aorta which func- tions as a blood-distributing apparatus. The median walls of the dorso- am Fig. 153.—Locusta.

RMRWWEPP–Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 CHAPTER XXI MYRIAPODA CHILOPODA, THE CENTIPEDES Scolopendra cingulata and dalmatica The Egg Cleavage and Blastoderm Formation.—The eggs of these two European centipedes are laid during June in the earth at a depth of 3 to 8 cm. in clumps of 15 to 20 or more, the female remaining curled around the mass until the young begin feeding. The short ovoid egg averages 3 mm. in length and has a

. Economic entomology. Beneficial insects; Insect pests; Thysanura. 14 JULID^, CASE Potatoes were forked out." But an examination of the structure of their mouth and jaws, at once shows that the Scolopendridse could never be vegetable feeders. There are two principles which it is safe to say Nature never deviates from. She never does any- thing without a purpose, and she never wastes her labour. If she endows an animal with any special structure or apparatus, it is for some end. Now it is obvious that if the centipedes feed on the roots of plants, they must sin against both of the above p Stock Photo

RMRDYMW7–. Economic entomology. Beneficial insects; Insect pests; Thysanura. 14 JULID^, CASE Potatoes were forked out." But an examination of the structure of their mouth and jaws, at once shows that the Scolopendridse could never be vegetable feeders. There are two principles which it is safe to say Nature never deviates from. She never does any- thing without a purpose, and she never wastes her labour. If she endows an animal with any special structure or apparatus, it is for some end. Now it is obvious that if the centipedes feed on the roots of plants, they must sin against both of the above p

RMRWRDDA–Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 Fig. 114:.—Libellula. (am) Amnion, {bid) Blastoderm, {gb) Germ band, {hi) Head lobe, {y) Yolk. periphery (Fig, 1135). In an egg six hours old two nuclei and three cytoplasmic masses appear, indicating this to be probably the eight-cell stage. The nuclei, as they migrate from the center of the egg toward the periphery, are surrounded by small amounts of cytoplasm. The yolk mass seems to

RMRF0990–. Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching. Embryology -- Insects; Embryology -- Myriapoda. 314 EMBRYOLOGY OF INSECTS AND MYRIAPODS that part surrounding the embryonic region, may now be designated as the "trophamnion." The first cleavage of the embryonic nucleus is completed at about the third day (Fig. 2615), two embryonic nuclei being then visible in the embryonic region. By the fifth day a second cleavage has taken place, producing four nuclei, the parasite having meanwhile considera

RMRWR977–Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 OLIGONEPHRIDIA 273 The head lobes at this time appear in cross section as two thickened areas continuous with the serosa {ser), forming the covering enclosing the yolk (Fig. 205C,hl). In a section closer to the pit through which the embryo is pushing into the yolk (Fig. 205B) the two furrows representing the cephalic end of the amniotic cavity are evident {am. cav). Still farther cephal

RMRF098C–. Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching. Embryology -- Insects; Embryology -- Myriapoda. 326 EMBRYOLOGY OF INSECTS AND MYRIAPODS The separation does not take place along the entire margin of the lateral plates simultaneously but occurs first at the cephalic end of the egg as a cap-like fold which grows rapidly caudad. A similar but slighter fold is later formed at the caudal end of the egg. The two folds eventually meet and coalesce near the caudal pole of the egg. At first the serosa consists

RMRWRDDB–Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 EPHEMERIDA, ODONATA, PLECOPTERA, ET AL. 193 indicating that maturation and fertilization occur previous to that time (Fig. 113A). A short time later, cleavage nuclei are on their way to the Fig. 114:.—Libellula. (am) Amnion, {bid) Blastoderm, {gb) Germ band, {hi) Head lobe, {y) Yolk. periphery (Fig, 1135). In an egg six hours old two nuclei and three cytoplasmic masses appear, indica

RMRD71G7–. A manual for the study of insects. Insects. 46 THE STUDY OF INSECTS. classed among our friends. And all of them are of interest to the naturahst as representatives of a distinct type of Arthropods. If we omit certain small and rather uncommon forms, the Myriapods may be classed in two orders ; one consisting of the Centipedes, the other of the Millipedes. Order Chilopoda (Chi-lop'o-da). The Centipedes, The centipedes can be recognized at a glance by the fact that each segment of the body bears a single pair of legs (Fig. 55). The body is usually flattened, and the antennae are long and many-

$Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 ^.- 4 Fig. 28. Fig. 29. Figs. 28, 29.—Two stages of embryos representing two periods in evolutionary history of insects, {abd) Abdomen, (ant) Antenna, (ant 2) Second antenna. (lb) Labium. {Ir) Labrum. (md) Mandible, {mx) Maxilla, (p) legs, (pleur) Pleuropodium. (pro.c) Protocephalon. (pic) Protocorm. (siom) Stomodaeum. (th) Thorax. {From Snodgrass.) among others, Lepisma, Gryllotalpa Stock Photo$

RMRWNFAD–Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 ^.- 4 Fig. 28. Fig. 29. Figs. 28, 29.—Two stages of embryos representing two periods in evolutionary history of insects, {abd) Abdomen, (ant) Antenna, (ant 2) Second antenna. (lb) Labium. {Ir) Labrum. (md) Mandible, {mx) Maxilla, (p) legs, (pleur) Pleuropodium. (pro.c) Protocephalon. (pic) Protocorm. (siom) Stomodaeum. (th) Thorax. {From Snodgrass.) among others, Lepisma, Gryllotalpa

RMREYJAR–. Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching. Embryology -- Insects; Embryology -- Myriapoda. OLIGONEPHRIDIA 273 The head lobes at this time appear in cross section as two thickened areas continuous with the serosa {ser), forming the covering enclosing the yolk (Fig. 205C,hl). In a section closer to the pit through which the embryo is pushing into the yolk (Fig. 205B) the two furrows representing the cephalic end of the amniotic cavity are evident {am. cav). Still farther cephalad the relation that

RMRWWBKF–Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 Fig. 301.—Diacrisia. Section through head at stomodaeum (stom). (am) Amnion. At 42 hours (Fig. 297C) the two anteriorly directed cephahc pouches so prominent in earlier stages (Figs. 297A,B) are still present, though they have become smaller and shallower. Just posterior to their dividing wall may be seen a mass of cells of the inner layer which in the middle is abdIO stom md abd9 Fi

RMRF0976–. Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching. Embryology -- Insects; Embryology -- Myriapoda. 364 EMBRYOLOGY OF INSECTS AND MYRIAPODS While the inner layer, which is to be described later, is forming, the embryo lengthens rapidly. The head end reaches the anterior pole of the egg at the twentieth hour and extends to the dorsal side where it develops into two hollow lobes. The posterior extremity in the mean- time pushes under the germ cells and grows into a spiral around the germ cells on the dorsal

RMRWWF0N–Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 mes mes mes Fig. 340.—Scolopendra cingulata. Cross sections A, B, successive stages, {hi) Blood cell, (dm) Membrana dorsalis. {ent) Entoderm cell, {mes) Mesoderm, {vm) Mem- brana ventralis. {y) Yolk, {yc) Yolk cell. {Adapted from Heymons.) germ disk becomes dispersed, migrating forward as two lateral mesoderm bands of cells. Meanwhile the ectodermal layer, except on the median line w

RMRF096D–. Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching. Embryology -- Insects; Embryology -- Myriapoda. A B Fig. 335.—Calliphora vomitoria. Section A is taken at the level of k of Fig. 329; B at the level of u. (ect) Ectoderm, {ent) Entoderm, {mes) Mesoderm. Posteriorly at this time the posterior mesenteron rudiment is divided api- cally into two branches in the same manner as the anterior rudiment. With the shortening of the embryo the proctodaeal opening comes to lie near the posterior end of the egg, with

RMRWWCD8–Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 irich Fig. 311.—Diacrisia Inner fold of amnion, (nc) Nerve cord, cell, {y) Yolk. Cross section through posterior end of 82-hour embryo, {am) {hi) Blood cells. (/) Fat body, {malp) Malpighian tubules. {prod) Proctodaeum. {tr) Tracheal invagination, {trich) Trichogen two ribbons of the mid-gut epithelium fuse ventrad of the yolk (Fig. 312, mge); at 84 hours and a little later the strips o

RMRF097H–. Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching. Embryology -- Insects; Embryology -- Myriapoda. 346 EMBRYOLOGY OF INSECTS AND MYRIAPODS and conspicuous, extending from the first gnathal head segment to the last abdominal segment. On each side of the neural groove the neuro- blasts are already distinct in each segment. Of these there are from two to four pairs in transverse section of the intermediate body segments (Fig. 304^), though they are not so regularly arranged as described by Wheeler (1889) fo

. Handbook of medical entomology. Insect pests; Insects as carriers of disease; Medical parasitology. Centipedes and Millipedes 25 THE MYRIAPODA, OR CENTIPEDES AND MILLIPEDES The old class, Mjoiapoda includes the Diplopoda, or millipedes, and the Chilopoda, or centipedes. The pres- ent tendency is to raise these groups to the rank of classes. The Diplopoda The Diplopoda, or millipedes (fig. 13), are character- ized by the presence of two pairs of legs to a segment. The largest of our local myriapods belong to this group. They live in moist places, feeding primarily on decay- ing vegetable matt Stock Photo

RMRE3J8W–. Handbook of medical entomology. Insect pests; Insects as carriers of disease; Medical parasitology. Centipedes and Millipedes 25 THE MYRIAPODA, OR CENTIPEDES AND MILLIPEDES The old class, Mjoiapoda includes the Diplopoda, or millipedes, and the Chilopoda, or centipedes. The pres- ent tendency is to raise these groups to the rank of classes. The Diplopoda The Diplopoda, or millipedes (fig. 13), are character- ized by the presence of two pairs of legs to a segment. The largest of our local myriapods belong to this group. They live in moist places, feeding primarily on decay- ing vegetable matt

RMREYFP1–. Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching. Embryology -- Insects; Embryology -- Myriapoda. MY RI APOD A 407 margins, antennal, mandibular, maxillary, postmaxillary (second maxil- lary), and three double thoracic segments. Pflugfelder (1932) suggests that the clypeus anlage may represent the preantennal segment, since it later contains a coelomic sac. The preoral part is double, as indicated by the presence of two pairs of coelomic sacs, but the division does not extend to the lateral margins. Lik

RMRDBE7B–. Agricultural zoology. Zoology. SCORPIONS, SPIDERS, MITES. 195 GLASS II.: MYRIOPODA (CENTIPEDES AND MILLIPEDES). Respiration by tracheae, as in insects. The body consists of a head and a large number of very similar segments, each of which possesses limbs. One pair of antennse. This class is divided into two orders: (1) that of Centipedes (Ghilopoda), with mouth-parts adapted for seizing prey, and one pair of legs to each segment; (2) that of Millipedes (Chilog- natha), adapted for de- vouring substances re- sembling humus, also the parts of plants; and two pairs of legs to each segment. Here

RMRF096K–. Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching. Embryology -- Insects; Embryology -- Myriapoda. 376 EMBRYOLOGY OF INSECTS AND MYRIAPODS The mesodermal tube continues to elongate, its caudal end being drawn more and more into the interior, thus becoming more and more angulated until at the time when the tube is at its maximum length the two limbs of the tube lie parallel with each other. Before the union of the mesenteron ribbons on the ventral side, clefts form laterally in the mesoderm, in which, at

. A manual of elementary zoology . Zoology. 268 MANUAL OF ELEMENTARY ZOOLOGY mites, ticks, etc.), and Centipedes belong to this group. Crustaceans have two pairs of antennae and are almost all water animals, breathing by gills. Insects have one pair of antennas and are usually land animals, breathing by air tubes and provided with wings. They have six legs. Arachnids have no antennas, nearly all breathe air by various devices, and have no wings, but eight legs. The Arthropoda are far more numerous than any other group of animals, and are of the greatest importance to man,. Fig. 172.—The Garden Stock Photo

RMRDJ3EW–. A manual of elementary zoology . Zoology. 268 MANUAL OF ELEMENTARY ZOOLOGY mites, ticks, etc.), and Centipedes belong to this group. Crustaceans have two pairs of antennae and are almost all water animals, breathing by gills. Insects have one pair of antennas and are usually land animals, breathing by air tubes and provided with wings. They have six legs. Arachnids have no antennas, nearly all breathe air by various devices, and have no wings, but eight legs. The Arthropoda are far more numerous than any other group of animals, and are of the greatest importance to man,. Fig. 172.—The Garden

RMRF0972–. Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching. Embryology -- Insects; Embryology -- Myriapoda. SIPHONAPTERA AND DIPTERA 367 At the fiftieth hour the cells lining the neural groove may be seen in cross section as two parallel vertical rows of neuroblasts formed in the neural ridge. They soon are modified as the ridge widens out and show the presence of ganglia before the sixty-fifth hour. The ganglia become distinct with the appearance of the neuropile. The ectoderm separates from the nerve cord at th

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