OVARY AND THE ANTERIOR PITUITARY BODY 169 



substance and oestrin does, however, lead to prolonged oestrus 

 (658 j. Zondek and Aschheim found that mice in premature 

 puberty will not mate owing to disparity of size. Smith 

 (580), however, reports that they will copulate at nineteen days 

 old if precocious puberty has been induced. Anterior pituitary 

 implants have a stimulating action on the testis of the young 

 male, with consequent acceleration of growth in the accessory 

 organs (626). 



Adult animal. Smith and Engle (581) have described the 

 effect of the anterior pituitary substance on the adult animal. 

 ' Super-ovulation ' of large numbers of follicles takes place in 

 the ovary, and oestrous changes occur in the accessory organs, 

 followed by an interval in which an irregular type of vaginal 

 smear is found. The ovaries of injected animals are found to 

 contain large numbers of corpora lutea, but these differ essen- 

 tially from the corpora lutea produced by sodium hydroxide 

 extracts in that they are normal corpora lutea resulting from 

 normal maturation and ovulation of Graafian follicles. Pro- 

 longed dosage will lead to the disappearance by ovulation of all 

 large-sized follicles from the ovary. 



Smith and Engle and also Zondek and Aschheim have found 

 very numerous true corpora lutea in ovaries of animals thus 

 treated, and the former workers have found up to forty-eight 

 ova in one Fallopian tube. Engle (177), however, found, in the 

 early stages of pregnancy, twenty-nine embryos at most after 

 such super-ovulation. Much thinning out must take place both 

 before and after implantation. 



Marrian and Parkes (439) have found that the anoestrous 

 period brought about in the rat by inanition or vitamin B 

 deficiency may be terminated by an oestrous period following the 

 administration of anterior pituitary substance. The typical 

 ovarian and extra-ovarian changes were produced. 



The pregnant animal. Zondek and Aschheim (659) and Engle 

 and Mermod (179) have described the effects of administering 

 anterior pituitary substance during pregnancy. The latter 

 found that pregnancy could be readily interrupted in the middle 

 third, though less easily later on. Ovulation occurred soon after 

 abortion, but not if pregnancy continued. Zondek and Asch- 

 heim found that although abortion could be caused, with 



