PLATE 1 



Fig. 1. A small piece of a vitelline membrane with adherent cicatricula in the 

 center of which the clear porus is to be seen. 



Fig. 2. The same magnified by a lens; the vesicle in the poms is obvious. 



Fig. 3. The cumulus of the cicatricula viewed from the side toward the interior 

 of the yolk; on its summit is a minute crater, the inner opening of the porus 

 (interna port apostomosis). 



Fig. 4. The same cumulus of the cicatricula seen from the other side. 



Fig. 5. The cumulus spread out in the bottom of a vessel after the water has 

 been removed, so that the porus is expanded and shows the vesicle at its center. 



Fig. 6. The vesicle brought more clearly to view after half of the substance of 

 the colliculus had been removed. 



Fig. 7. The vesicle after the cicatricula was turned over. Profile view. 



Fig. 8. The vesicle attached to a portion of vitelline membrane. 



Fig. 8>1<. A part of vitelline membrane with traces of the zonule and of the torn 

 vesicle. 



Fig. 9. Vesicle and colliculus cut through the middle. 



Fig. 10. Magnified cicatricula of a laid egg with the double circle of the blasto- 

 derm and the whitish nucleus in the center. 



Fig. 11. The same cicatricula with the internal circle of the blastoderm re- 

 moved, so that the fluid cavity with the uncovered nucleus and the farinaceous 

 granules may be seen. 



Fig. 12. Immature ovarian ovule in which a trace of a cicatricula is to be 

 discerned. 



Fig. 13. Same cicatricula removed from the ovule hanging to a bit of vitelline 

 membrane. 



Fig. 14. An even smaller ovarian ovule with a suggestion of the vesicle. 



Fig. 15. The same containing the vesicle cut open and magnified. 



Fig. 16. The yolk divided by a perpendicular cut beginning at the cicatricula. 

 In the center the latebra containing a white fluid; from it a canal is continued 

 to the cicatricula. 



Fig. 17. Yolk cut horizontally; the varicolored strata of yolk material are 

 visible. 



Fig. 18. Portion of yolk with canal to cicatricula. 



Fig. 21. A yolk with first stratum of albumen from which the chalaziferous 

 membrane arises; attached to it are the first beginnings of the chalazae which 

 are found above and below it among the folds of the oviduct. 



Fig. 22. Shows the lamellar structure of the albumen surrounding the yolk. 



Fig. 22*. A part of the chalaza cut off, within it a canal is seen produced by the 

 spirals of the internal strand of the chalaza. 



Fig. 23. Part of a vitelline membrane with attached chalaziferous membrane 

 continued into the chalaza [see plate 2]. 



Fig. 24. Yolk with its chalazae and the whitish girdle of Vicq d'Azyr. 



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