File:Journal of morphology (1909) (14586949950).jpg

Identifier: journalofmorphol20wist (find matches)
Title: Journal of morphology
Year: 1909 (1900s)
Authors: Wistar Institute of Anatomy and Biology
Subjects: Morphology Physiology
Publisher: Boston : Ginn & Co.
Contributing Library: MBLWHOI Library
Digitizing Sponsor: MBLWHOI Library

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of the yolklying beneath the floor of the cavity. These yolk masses (m) are non-nucleated. X 246. Fig. 47. The anterior portion of a longitudinal section from a blasto-derm taken forty hours after fertilization. The remains of the subgerminalcavity not yet penetrated by the entoderm (e) is full of yolk masses, someof which are undergoing fragmentation ((?m). X 245. Fig. 48. The right side of a median transverse section taken one hourafter incubation. The lateral edge of the entoderm is shown at e andthe inner margin of the germ-wall at y. The space between these twopoints can be followed along the entire right side, showing that the fusionbetween the lateral margin of the entoderm and the inner edge of the germ-wall had not yet taken place. X 245. Fig. 49. The central part of a section taken through v-v of Fig. VIII.At s is shown a segmentation cell that has loosened and sunk down fromthe underside of the ectoderm, x 245. t Gastrulation in the Pioeons Egg.J. Thos. Patterson. Plate VI.
Text Appearing After Image:
The Journal of Morphology—Vnr.. xx. No. 1. Plate VII. Fig. 50. This embryo shows the result of the operation described in Ex-periment II (page 93). The injury was made on the posterior edge ofthe dorsal lip, thirty-five and three-fourths hours after fertilization. Theegg was then incubated for forty-nine hours. The anterior end of theembryo is normal in every way, and nineteen pairs of somites are devel-oped. The depth to which it was necessary to focus the microscope inorder to obtain an image of the injured material in the entoderm can beseen by the fact that the somites are out of focus, x 30. Fig. 51. A transverse section through the injured region of the preced-ing embryo (Fig. 50, op). The affected cells lie in the entoderm, x 95 Figs. 52, 53, and 55 are all from an unincubated blastoderm. Fig, 52 showsthe entoderm and part of the ectoderm above, and a free nucleus at n lyingon the floor of the cavity, which contains many small granules, x 688. Fig. 53. It shows two small nucl

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