File:Conklin 1905 fig34-35.jpg

Fig. 34 - 35

Figs. XXXIX, XL. Diagramatic representations of the types of germinal localization in ascidians and annelids. Mesodermal substance is shaded by lines, neural substance by fine stipples, and chorda material by coarse stipples. Fig. XXXIX, the ascidian type; egg viewed from right side. The mesoplasm, composed of mesenchyme (m'ch) and muscle substance (msl, is represented in its final position, which it assumes before the first cleavage. The neural plate (n. p.) and chorda (eh.) substances are not distinguishable in the unsegmented egg. but are here shown in the positions in which they appear at the 2-cell stage; the chorda and mesenchyme substances should be shown as meeting on the side of the egg, thus forming a chorda-mesenchyme ring around the endoderm. The ectoplasm (ect.) and endoplasm (end.) are localized, as here represented, at the close of the first cleavage. Fig. XL, the annelid type; egg viewed from left side. The substances of the first and second somatoblasts (the former stippled along one border, the latter shaded by lines) are shown in the positions in which these cells are ultimately formed ; in the unsegmented egg the lobe which contains the substances of these cells lies nearer the lower pole. The substances of the cerebral ganglion (c. g.), ventral ganglia (v. g.) and prototroch (proto.) are not distinguishable in the unsegmented egg, but are shown in the regions to which they may be traced by means of the cell lineage.

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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 fig34-35.jpg. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/File:Conklin_1905_fig34-35.jpg

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