248 Mr. E. A. S chafer. On Immature Ovarian Ovum [Mar. 18, 



Fig. 2. Germinal spot of small ovum showing matrix and imbedded granules com- 

 posing the macula. 



m. v. Membrane of germinal vesicle to which the macula is adherent. 



ma. Homogeneous matrix of germinal spot in which darkly stained granules 

 are imbedded. 



Diameter of ovum "488 millim. Magnified 250 diameters. 

 Kg. 3. G-erminal vesicle and germinal spot of a very small ovum. 

 m. v., ma., as before. 



c. Central clear part of macula. (Diameter of ovum '122 millim. ; of 

 germinal vesicle '054 millim.) Magnified about 600 diameters. 

 Tig. 4. Macula germinativa of a very small ovum. (Diameter of ovum '122 millim. ; 



of macula '049 millim.) Magnified 400 diameters. 

 Fig. 5. Small Graafian follicle with ovum, showing two or three nucleus -like con- 

 densations of the vitellus. (Diameter of ovum '3 millim.) Magnified 

 120 diameters. 



Fig. 6. Smaller ovum ('264 millim.) than that represented in fig. 5, but more highly 



magnified, showing a condensation, c, of the vitelline network. 

 Fig. 7. Small piece of the wall of the germinal vesicle of a moderately sized ovum 

 (l - 07 millim., germinal vesicle '195 millim). 

 (a.) On the flat. 

 (b.) Seen in optical section. 



The membrane is seen to have a granular appearance. 

 Fig. 8. Yery small ovarian ovum (diameter '11 millim.) with follicular epithelium, 

 germinal vesicle, and germinal spot ; and with a peculiar insulated 

 body in the vitellus, which is apparently the remains of a second 

 germinal vesicle and spot in process of disappearance. 

 Fig. 9. Part of a small ovum ('3 millim.) with two pseudo-nuclei in vitellus. 



f. e. Follicular epithelium. 



y. Yolk substance forming a network. 



g. v. Part of the germinal vesicle. 



Fig. 10. Superficial layers of a comparatively large ovum (1*586 millim.) 

 f. e. Follicular epithelium. 

 jo. Pyriform cell. 



I. Clear superficial layer of vitellus ; II. Finely granular layer— its 

 granules are largest near tho first layer ; III. White yolk ; 

 IY. Superficial part of yellow yolk. Drawn under a magnifying 

 power of about 500 diameters. 

 Fig. 11. Superficial part of a still larger ovum (2'44 millim.). 

 f. e. Follicular epithelium. 

 z. r. Zona radiata. 



Fig. 12. Thick section of a comparatively large ovum, showing the peculiar systems 

 of fibres described in the text. Slightly magnified (about 10 

 diameters) . 



Fig. 13. The upper part of the previous figure. Magnified 40 diameters. 

 Figs. 14 to 26 are from sections of rabbits' ovaries. 



Fig. 14. Small Graafian follicle, the follicular epithelium forming a single layer of 

 columnar cells. 



v. g. Germinal vesicle, the wall of which seems to be deficient at this 

 part. 



m. Macula, composed of a mass of granules, imbedded in a homogeneous 

 matrix. 



n. Nucleus in the periphery of the vitellus. 570 diameters. 

 Fig. 15. Small Graafian follicle, not yet completely cut off from the rest of the 



