6o 



INTERNAL SECRETIONS OF THE OVARY 



Ferret. Reproduction in the ferret has been studied by 

 Marshall (441) and Hammond and Marshall (267) . The breeding 

 season in the ferret lasts from about March to August, and 

 ovulation can take place at any time during this period, provided 

 that copulation occurs. Ripe follicles are always present in the 

 unmated female during the breeding season. 



r.a 



,_ c.t. 



m. 



Section of Lobule of Mammary Gland of 

 Rabbit during Pseudo-Pregnancy. 



Fig. 33 



c.t. connective tissue; m. muscle; r.a. rudimentary alveoli 



The pseudo-pregnant period which follows sterile copulation 

 is remarkable in that it lasts six weeks, as long as true pregnancy. 

 In this characteristic the ferret is without parallel among known 

 Eutheria, except possibly the dog. CEstrus returns about eight 

 weeks after sterile copulation. 



The ferret is also peculiar in showing a prodigious growth of 

 the vulva at oestrus. This swelling, which begins at the onset of 

 cestrus, reaches its maximum size in two to three weeks, and is 

 maintained during the whole of the breeding season in the 

 absence of copulation. The hypertrophy, which enlarges the 

 oestrous vulva to about fifty times the anoestrous size, dis- 

 appears at the beginning of pregnancy, pseudo-pregnancy, or 

 anoestrus. 



The uterus also shows well marked development during 

 oestrus, but this is continued and increased after ovulation. 

 During anoestrus the uterus is very small and its glands com- 

 paratively undeveloped. At the beginning of cestrus the uterus 

 enlarges, and the mucosa and glands are rather better developed. 

 The uterus remains static in this condition during the whole 



