24 



EDWARD MCCRADY, JR. 



-F. 



Fig. 5 Female urinogenital system. A, ventral view of adult organs in 

 anoestrous condition. B, dissection of the same specimen. The uteri are seen to 

 be completely double, each protruding into its own median vaginal cul-de-sac. 

 From this median position the vagina runs anteriorly and laterally, and then 

 turns back upon itself to empty into the urinogenital sinus immediately dorsal 

 to the neck of the bladder. The ureter on each side passes between the arms 

 of the lateral vaginal loop to enter the bladder through a prominent papilla on 

 the dorsal side of the neck of this organ. The urinogenital sinus and the 

 rectum open to the exterior separately, but very near each other. There is no 

 cloaca. The anal musk glands, which are here shown fully distended, open 

 exteriorly through two very small pores. C, the ventral wall of the urino- 

 genital sinus shows a bifurcate glans clitoridis. The skin fold beyond this 

 point is the prepuce. 



II. THE FIRST DAY 



Stage 1. Fertilization. The tubal ovum. 



Fertilization. As the ovum can descend the oviduct in as 

 short a time as 24 hours (Hartman, '28), and as it comes to 

 be surrounded by an impenetrable layer of albumen and a 

 thin shell membrane while doing so, and as unfertilized eggs 

 begin to degenerate within 24 hours (S. C. Smith, '25), it is 

 necessary for the spermatozoon to find the ovum at the ex- 

 treme upper end of the oviduct, and soon after ovulation, if 

 fertilization is to be accomplished. But ovulation does not 

 bear a precise or consistent time relation to copulation. Some- 



