File:Conklin 1905 fig21-24.jpg

Figs. XXI-XXIV. Sections of eggs of Cynthia partita

Figs. XXI and XXIV in the median plane. Fig. XXIII a little to one side of the median plane at the posterior end, Fig. XXII in a transverse plane. Fig. XXI represents a 64-cell stage, Fig. XXII a 64-76 cell stage. Fig.XXIII a 76-110-cell stage, and Fig. XXIV a 110-cell stage. The clear protoplasm, the yellow protoplasm and the yolk are represented as in the preceding figures. The clear protoplasm is localized chiefly in the ectoderm and neural plate cells, the yellow protoplasm in the crescent cells (mesoderm) and the yolk in the endoderm and chorda cells; yolk is also present in the inner ends of the ectoderm and mesoderm cells. The polar hodies shown in Fig. XXIII in dotted outline do not lie in the plaueof the section drawn, but in that of the next section of the series. It is probable that the neural plate and chorda cells of this figure (k~-* and A>3) have already divided in a transverse plane {v. fig. 131), and that these cells should therefore be labelled A 8 *? and \ a> in Fig. XXIV. In Fig. XXII the mesoderm cell B 6 - 2 (Fig. XVIII.i has divided into a mesenchyme cell (B"-3) and a muscle cell IB'"*), the former containing little and the latter much of the yellow protoplasm.

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Conklin Figures: Fig 1-2 | Fig 3-6 | Fig 7-8 | Fig 9-12 | Fig 13-16 | Fig 17-20 | Fig 21-24 | Fig 25-26 | Fig 27-33 | Fig 34-35 | Plate I | Plate II | Plate III | Plate IV | Plate V | Plate VI | Plate VII | Plate VIII | Plate IX | Plate X | Plate XI | Plate XII

Reference

Conklin EG. The Organization and Cell-Lineage of the Ascidian Egg (1905) J. Acad., Nat. Sci. Phila. 13, 1.

Conklin 1905 TOC: I. The Ovarian Egg | II. Maturation and Fertilization | III. Orientation of Egg and Embryo | IV. Cell-Lineage | V. Later Development | VI. Comparisons with A.mphioxus and Amphibia | VII. The Organization of the Egg | Summary | Literature Cited | Explanation of Figures

Cite this page: Hill, M.A. (2024, April 27) Embryology Conklin 1905 fig21-24.jpg. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/File:Conklin_1905_fig21-24.jpg

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