544 FOOT AND STROBELL. [Vol. XVII. 



EXPLANATION OF PLATE XLII. 



The photos of this plate show osmophile granules in the ovarian eggs — from 

 the smallest cells near the proximal end of the ovary (cells in which the first trace 

 of archoplasm is seen) to the large oocytes, first order, at the distal end of the 

 ovary. These granules are also shown in the large and capillary spaces between 

 the oocytes, in the membrane or capillary space within the membrane surrounding 

 the eggs, and in the cells around the ovary. All the photos except No. yj were 

 taken from unstained preparations, ' and the magnification is the same for all, 

 with one exception, No. 38 When using a fixative not containing osmic, the 

 ovaries after fixation were always put in this acid for a few minutes, in order 

 to blacken the deutoplasmic (osmophile) granules. These granules are sharply 

 differentiated in the unstained preparations, as no other structure in the cell 

 shows this reaction to the osmic. They can be readily seen in cells where it is 

 impossible to identify them after staining. Where the archoplasm is differen- 

 tiated, it is due to a yellowish tint produced by the fixative. 



Photo 28, section (2^;a) of two very young oocytes, near the proximal end of 

 the ovary, each .showing osmophile granules. The archoplasm in these cells is at 

 the same early stage of development shown in the stained preparation of Photo i, 

 PL XLI. Fixative, corrosive acetic, followed by osmic acid. 



Photo 29, section (2-J- p) of three young oocytes, each showing one or more 

 osmophile granules. The archoplasm in these cells resembles closely that of the 

 stained preparation of Photos i and 2, PI. XLI. Fixative, Graf's picro-formalin, 

 followed by osmic acid. 



Photo 30, section (2^^) of a young oocyte. One osmophile granule at the 

 periphery of the small mass of archoplasm, which is faintly differentiated even in 

 the unstained preparation. For a sharp differentiation at this stage, see Photos 

 3, 4, and 6 of the stained preparations of PI. XLI. Fixative, Hermann's fluid. 



Photo 31, section (^-\ii) of a young oocyte. One osmophile granule nearly in 

 the center of the small mass of archoplasm, which is in contact with the nuclear 

 wall (cf. Photos 3, 4, and 6, PI. XLI, for stained preparations of archoplasm at 

 this stage). Fixative, Hermann's fluid. 



Photo 32, section (2j/u) of a young oocyte. Two large osmophile granules. 

 The cell contains the amount of archoplasm usual at this stage of development 

 {cf. with stained preparations shown in Photos 3, 4, and 6, PI. XLI). Fixative, 

 Hermann's fluid. 



Photo 33, section (2^^) of young oocyte. Two osmophile granules nearly in 

 contact. See Photos 3, 4, and 6 for stained archoplasm at this stage. Fixative, 

 Hermann's fluid. 



Photo 34, section (2\p) of young oocytes, showing osmophile granules and 

 archoplasm. In the largest cell there are four osmophile granules, in the smallest 

 three, and in the cell on the right there are two. A dark print was made of this 

 preparation, in order to show the archoplasm in the two cells on the right. The 

 archoplasm in the largest cell is not unlike that shown in Photo 5, PI. XLI. 

 Fixative, Plat-acetate-formalin, followed by osmic acid. 



Photo 35, section (2-J-/x) of a young oocyte. Five osmophile granules can be 

 seen in the section, though the archoplasm is still in close contact with the 



