102 THE PHYSIOLOGY OF REPRODUCTION 



degenerative changes comparable to what occur normally in the 

 pseudo-pregnant bitch (p. 98). The mammary glands also develop 

 (p. 617) and secrete milk. The entire pseudo-pregnant period is 

 somewhat less in duration than true pregnancy, which in the rabbit 



.^' 



.iif 







,p o Q ., 



\ Q 









6 



Fig. 21. — Section through uterine luuco.ia of rabbit twenty-four days after 

 sterile coition (leti'ogi-essive. stage in pseudo-piegnanc}'). A great 

 quantity of extiaAasatecl blood is seen. The glands are still somewhat 

 enlarged. (From Hammond and Mar.shall.) 



lasts thirty days. Exceptionally (as when two doe rabbits "jump " 

 one another and show sexual excitement), ovulation followed by 

 pseudo-pregnancy may take place without coition having occurred.^ 

 In the guinea-pig Stockard and Papaniculaou - have described a 



' Hammond and Marshall, loc. rlt. 



- Stockard and Papanicolaou, " Tlie Existence of a Typical (Jistrous Cycle in 

 the Guinea-Pig," Amer. Jour, of Anat., vol. xxii., 1917. 



