File:Conklin 1905 plate03.jpg

Plate III Living Eggs of Oynthia partita - First to Fourth Cleavage

Figs. 25 and 26. Same egg as the one shown in figs. 21-24; final stages in the first cleavage.

Fig. 27. Another egg at the close of the first cleavage ; seen from the posterior pole.

Fig. 28. End view of egg of same stage as preceding, showing the lateral limits of the yellow crescent, the clear protoplasm in the upper hemisphere and the yolk in the lower. The anterior portion of the lower hemisphere is composed of light gray material ; this is the gray crescent and gives rise to chorda and neural plate.

Fig. 29. Four-cell stage, viewed from the animal pole.

Fig. 30. Similar egg seen from the vegetal pole; the crescent covers about half of the posterior blastomeres.

Fig. 31. Fight-cell stage: the crescent is limited entirely to the two posterior blastomeres at the vegetal pole : while under observation the furrow between B 4' and b 4-2 shifted from the position indicated by the faint line to that shown by the heavy line, thus giving rise to the "cross furrow" shown in the next figure.

Fig. 32. Fight-cell stage, viewed from the right side, showing a small amount of yellow protoplasm around all the nuclei.

Fig. 33. Same stage viewed from the vegetal pole, showing 1% yolk laden endoderm cells and the crescent.

Fig. 34. Same stage viewed from the posterior-animal pole showing the clear ectodermal cells and the crescent.

Fig. 35. Same stage seen from the anterior-vegetal pole; yellow protoplasm around all the nuclei.

Fig. 36. Fourth cleavage of the egg seen from the vegetal pole.

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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 26) Embryology Conklin 1905 plate03.jpg. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/File:Conklin_1905_plate03.jpg

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