238 INTERNAL SECRETIONS 



also upon the age of the ovary at the time of transplantation. 

 In accordance with Steinach, Athias points out that the number 

 of the atretic follicles is very great in the ovarian graft, and 

 that the theca interna is highly hypertrophied. The richly 

 vascularized stroma is full of nests of interstitial cells. Lately 

 Athias (1922) has given a full account of his histological work 

 on ovarian grafts; he insists especially on the tendency of the 

 graft to undergo cystic degeneration. According to Moore 

 (1921 a) corpora lutea do not develop when the ovary is en- 

 grafted into a male which has not been previously castrated. 



It seems evident that the time at which the more or less 

 complete transformation of follicles into interstitial tissue 

 will have occurred, must differ from case to case. For instance 

 Marshall and Jolly found once in autotransplantation a 

 normal condition of the ovary fourteen months after the 

 operation; in a case of homoiotransplantation the ovary was 

 still normal six months after the the operation. (In both cases 

 the ovary was implanted into the kidney). If now we compare 

 these statements, which are only instances of what was seen by 

 several other observers after autotransplantation and homoio- 

 transplantation of the ovary, with the statements of Steinach 

 and Athias concerning the condition of the ovary engrafted 

 into the male, it seems that the results are different according 

 to the sex of the animal into which the ovary was engrafted. 

 The difference is indeed mainly a quantitative one. The 

 follicles of an ovarian graft in a castrated male are possibly 

 less able to attain ripeness and to form corpora lutea; follicular 

 atresia is probably augmented in such grafts, and conse- 

 quently an hypertrophy of the interstitial tissue must finally 

 take place. A detailed study of this special question was 

 made by Sand (1918, pp. 121 -51) in a very great number of 

 experiments on rats and guinea pigs. On examining the grafts 

 about six months or less after the operation he confirmed the 

 fact that the follicles can ripen in the ovarian graft; in the 

 majority of his experiments Sand also found corpora lutea. 

 In regard to the comparative condition of the graft in castrated 

 females and castrated males, Sand states that there is in the 

 latter a tendency to an intensified follicular atresia, and to an 

 increase of interstitial cells derived from the theca intema; 

 he concludes that the follicles are in the male really less able 

 to ripen and to form corpora lutea. We do not yet understand 



