Katliarine Foot and E. C". 8ti-obcll 23 ^ 



Photo. 8. x 1000. Next section to Photo. 7 showing the same large nucleo- 

 lus and a second accessory nucleolus stained Ijlack. at the upper left hand 

 periphery of the germinal vesicle. 



Photo. 9. x 1000. Second section from Photo. S showing a third accessory 

 nucleolus which in this section is attached to one of the chromatic filaments. 



Photo. 10. x 1000. Section of an oocyte first order from a receptaculum 

 ovorum, at the same stage of development as those shown in Photos. 1 to 9. 

 The archoplasmic granules are aggregated at two poles of the oocyte bearing 

 a striking resemblance to the polar rings of the ripe egg. Only one pole is 

 shown in the photograph. 



Photo. 11. x 1000. Section of germinal vesicle of an oocyte first order 

 from a receptaculum ovorum, showing black chromatic filaments and one 

 accessory nucleolus attached to the longest filament. This was the only acces- 

 sory nucleolus in this germinal vesicle, and the principal nucleolus stained 

 brownish yellow as in the other oocytes. 



Photo. 12. x 710. Young oocyte from ovary showing the large vacuolated 

 nucleolus and well defined areas of archoplasm in the cytoplasm. On the 

 periphery of the photograph is shown part of a very small oocyte with aggre- 

 gations of archoplasm (yolk nucleus) at opposite poles of the germinal vesicle. 

 Fixative, corrosive sublimate (saturate). Stain, iron haematoxylin. 



Photo. 13. X 1000. Part of periphery of oocyte first order from a receptac- 

 ulum ovorum. The two membranes, with an indication of the substance 

 between, are distinctly shown. The archoplasm is fused with the cytoplasm 

 in a form characteristic of chromo-acetic fixation, c. f. Photo. 10 for platino- 

 osmic fixation. Fixative, chromo-acetic. Stain, iron haematoxylin followed 

 by dilute Bismarck brown. 



Photo. 14a. x 1000. Nucleolus with black granules in large unstained 

 oocyte from ovary. The granules resemble the black granules found in the 

 cytoplasm of the same preparation. Fixative, chromo-acetic followed by osmic 

 acid, which blackened the granules of the nucleolus and cytoplasm. 



Photo. 14b. x 1000. Nucleolus in a large unstained oocyte from distal 

 end of ovary. Fixative, Hermann's fluid. 



Photos. 15, 16 and 17. x 700. Vacuolated nucleoli from large unstained 

 oocytes from ovary. Fixative, Hermann's fluid. 



Photo. 18. x 700. Vacuolated nucleolus in medium sized unstained oocyte 

 from ovary. Fixative, Hermann's fluid. 



Photos. 19, 20 and 21. x 700. Vacuolated nucleoli in large unstained 

 oocytes from ovary. Photo. 21 shows both a principal and accessory nucleo- 

 lus. Fixative, picro-nitric followed by osmic acid. 



PLATE II. 



The section of Photo. 26 is 2 /t. All the others are 2^^ /i. 



Photo.s. 22-25. x 1000. Four sections selected from fourteen of a germinal 

 vesicle of an oocyte first order from a receptaculum ovorum. The principal 

 nucleolus is present in three consecutive sections, two of them being shown in 

 Photos. 22 and 23. Photo. 23 shows one accessory nucleolus attached to the 

 largest chromatic filament. Fixative, Rabl's picro-sublimate. Stain, iron 

 haematoxylin, followed by dilute Bismarck brown. 

 17 



