INTERNAL SECRETION OF CORPUS LUTEUM 185 



entirely dependent upon the presence of the corpora lutea and 

 could be prevented by their removal after ovulation. 

 The removal of both ovaries has a similar effect in pre- 

 venting this response of the uterus to mechanical irritation. 

 Loeb also found that the sensitivity appeared at a certain 

 definite time after ovulation. These deciduomata were entirely 

 reabsorbed before the occurrence of the next oestrous period and 



■r::33?^^I}^^» 



Fig. 64. — Uterus of Mouse (after sterile copulation) 

 WITH Deciduoma. 



/. ]umen; d. deciduoma. 



were shown by Loeb to have no effect upon the length of 

 functional life of the corpus luteum. Pregnancy, however, by 

 prolonging the life of the corpora lutea, prolongs the life of 

 deciduomata. Corner and Warren (130) and Frank (219) were 

 able to produce the same reaction in the rat during lactation. 

 Long and Evans (425), also working on the rat, found that the 

 uterus in this anim.al was quite unable to respond to mechanical 

 stimulation at any stage of the normal unmated cycle. These 

 authors, however, confirmed the report that the sensitivity did 

 appear in the rat during pseudo-pregnancy and lactation, 

 when the corpora lutea undergo a degree of development not 



