66 



FRANK R. LILLIE. 



bers. In the male (Fig. 12) the germinal epithelium is already 

 reduced to a single layer of nuclei, the albuginea has undergone 



Fig. 9. Normal female, 3.6 mm. greatest length (No. 54c) X 6. 1. Gonad; 

 2. Wolffian body; 3. Vena cava inferior; 4. Miillerian duct; 5. Wolffian duct; 

 6. Allantois ; 7. Umbilical artery; 8. Homologue of scrotal sac of male; 9. 

 Phallus; 10. Inguinal ligament. 



definite fibrous differentiation, and the primary sex cords are form- 

 ing definite tubule rudiments with abundant interstitial tissue be- 



