1910-11.] Development of Germ Cells in Mammalian Ovary. 1 77 
(27) Yon Winiwarter, H., et Sainmont, G., Arch. f. Biol., t. xxiv., Aout 1908, 
Avril et Septembre 1909. 
(28) Waldeyer, W., Eier stock u. Ei, Leipzig, 1870. 
(29) Weigert, K., Zeit.f. Mikros., Bd. xxi., 1904: “Eine kleine Verbesserung 
der Hamatoxylin — Van Gieson Methode.” 
(30) Whitridge Williams, F., Johns Hopkins Hosp. Rep., iii., 1892 : “Papillo- 
matous Tumours of the Ovary ” 
(31) Wendeler, Martin’s Kranklieit der Eierstocke, etc., 1899. 
(32) Wilson, E. B., The Cell in Development and Inheritance , 1906. 
DESCRIPTION OF FIGURES. 
Fig. 1. Pig embryo, 12 cm., photo, x 20 d., showing cortical and medullary 
zones. 
Fig. 2. Pig embryo, 14 cm., photo, x 90 d., showing primitive follicles in cortex 
and blood sinuses in medulla. 
Fig. 3. Pig embryo, 14 cm., drawing oc. 6, y 1 ^ ol. i. Z., primitive follicle, with 
oocyte and follicle cells surrounding it. 
Fig. 4. Pig embryo, 14 cm., drawing oc. 6, T y ol. i. Z., cells from capsular 
epithelium, darker in staining than oogonia underlying them. 
Fig. 5. New-born puppy, photo, x 300 d., showing capsular epithelium on 
surface, nests of cells throughout cortex. 
Fig. 6. Neiv-born puppy, drawing, 6 oc. J. Capsular epithelium seen, cells 
underneath large and clear, first stage of oocyte, one cell seen in mitosis. 
Fig. 7. New-born puppy , photo, x 500 d. Cell nests in cortex. Large solitary 
cell seen. 
Fig. 8. N ew-born puppy , drawing, oc. 6, ol. im. y^. Z., oocyte in the various stages 
of synapsis. 
Fig. 9. New-born puppy , photo, x 1-000 d. Group of oocytes in stage of 
synapsis. To left of field are cells in reticulum stage. 
Fig. 10. New-born puppy, photo, x 600 d. “Reserve” and interstitial cells in 
central portion of cortical zone. 
Fig. 11. New-born puppy, photo, x 1000 d. Mitosis occurring in oocytes of the 
first stage. 
Fig. 12. Neiv-born puppy, schematic drawing of cortex, showing capsular 
epithelium, oocytes in various stages. Blood sinus. Masses of reserve cells near 
the centre. 
Fig. 13. Three months old puppy, photo, x 300 d. Surface of ovary, capsular 
epithelium cut obliquely. Glandular-like spaces seen. 
Fig. 14. Three months old puppy, follicle with oocyte in centre. 
Fig. 15. Three months old, puppy, photo, x 600 d. Follicles in deeper layers of 
ovary, oocytes showing double threads in a reticulum, with well-marked nucleolus 
and a great quantity of cell deutoplasm. 
Fig. 16. Three months old puppy , drawing, y 1 ^ ol. im. oc. 6. Follicle showing 
resting nucleus of oocyte (a) ; nucleus fallen out (b) ; follicle cells dividing up 
oocytes (c) ; stroma cells (d) ; isolated follicle (e). 
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