Bulletin of the Museum of Comparative Zoology at Harvard College . Phylactoltematous larva, its larval digestivetract having dropped out from the ontogeny, so the mouth and anus ofGymnolsemata are precociously formed on the pole opposite the blasto-pore, the primitive stage during which they existed at the blastoporicpole having dropped out of the ontogeny. It is well known from the works of Harmer (86) and Seeliger (89), MUSEUM OF COMPAKATIVE ZOOLOGY. 105 that iu Pedicelliua, iu which the metamorphosis of the larva has beeu beststudied, the stolon arises from the base of the stalk — that is,

- Image ID: 2AJ31C2
Bulletin of the Museum of Comparative Zoology at Harvard College . Phylactoltematous larva, its larval digestivetract having dropped out from the ontogeny, so the mouth and anus ofGymnolsemata are precociously formed on the pole opposite the blasto-pore, the primitive stage during which they existed at the blastoporicpole having dropped out of the ontogeny. It is well known from the works of Harmer (86) and Seeliger (89), MUSEUM OF COMPAKATIVE ZOOLOGY. 105 that iu Pedicelliua, iu which the metamorphosis of the larva has beeu beststudied, the stolon arises from the base of the stalk — that is,
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Image ID: 2AJ31C2
Bulletin of the Museum of Comparative Zoology at Harvard College . Phylactoltematous larva, its larval digestivetract having dropped out from the ontogeny, so the mouth and anus ofGymnolsemata are precociously formed on the pole opposite the blasto-pore, the primitive stage during which they existed at the blastoporicpole having dropped out of the ontogeny. It is well known from the works of Harmer (86) and Seeliger (89), MUSEUM OF COMPAKATIVE ZOOLOGY. 105 that iu Pedicelliua, iu which the metamorphosis of the larva has beeu beststudied, the stolon arises from the base of the stalk — that is, at the polewhere mouth and anus were first formed — at the pole of invagination.I have shown that this is true for Phylaotolaemata, and probably forGymuolsemata. If the interpretation which I have put on Gymnolsematous ontogeny becomes confirmed, the larvae and the budding areas will be homologous throughout all Bryozoa. The following diagrams will explain my idea of the relation of the different ontogenetic stages in the two groxips. Endoprocta. Ectoprocta.. The left hand vertical series represents stages in the development ofEndoprocta ; the right hand one, stages of Ectoprocta. The blastopore (*)is throughout turned upwards in the figures. Stage I. is in both cases ayoung gastrula. Stage II. is that of the free-swimming larva of Endo-procta. This stage is lost iu the ontogeny of Ectoprocta, in which, byabbreviation of larval life, the free-sw-imming stage corresponds to thecondition of the fixed Endoproct after it has undergone its rotation.This stage, or one slightly later, is shown in III. Both larvae are fixed,the Endoproct by the blastoporic, the Ectoproct by the opposite pole.The position of the stolon, or of the first polypide of the colony producedby non-sexual methods, is represented at gm., near the blastoporic pole. 106 BULLETIN OF THE Summary. The following general scheme of the budding process iu Ectoprocta,derived from my own and other recent studies, may be