354 THE PHYSIOLOGY OF REPRODUCTION 



breeding season, large follicles were found in the grafts, wliile at a 

 later period corpora lutea were present, showing that ovulation had 

 occui-i'ed in tlie transplanted ovaries. In (me case, a homoplastic 

 graft was found to be normal after fourteen months, while a normal 

 heteroplastic graft was composed entii'ely of healthy ovarian tissue 

 (with follicles and ova) after six months. In these experiments the 

 ovaries were grafted into the sidjstance of the kidneys. 



Homoplastic transplantation was 

 found to be more easily accom- 

 plished than heteroplastic trans- 

 plantation. This result could hardly 

 be ascribed to increased difficvdties 

 in the performance of the latter 

 operation, since the techniipie was 

 identical in each case. Further- 

 more, oni- successes in heteroplastic 

 transplantation Avere usually olitained 

 in experiments in which two rats 

 from the same litter were known to 

 have been employed, so that the 

 (^varies were grafted into whole 

 sisters, but we were not sure of the 

 relationship in every case. 



These experiments clearly indicate 

 that the nature of the (jvarian influ- 

 ence is chemical rather than nervous, 

 since the successfully grafted ovaries, 

 while still maintaining their func- 

 tions, had lost their normal nervous 

 connections. It is probable, there- 

 fore, that the uterus depends for its 

 proper nutrition upon sulistances 

 secreted by the ovaries. 



Further evidence in support of 

 tlie view that the (.)vary produces an 

 liy the results of ovarian medication 

 or the administration of preparations of ovarian substance for 

 medicinal purposes. It is somewhat difhcult, however, to know 

 precisely what value to assign to this practice about which medical 

 authorities still appear to differ. Bi'own-Sequard ^ seems to have been 

 the first to employ ovarian exti'acts medicinally. He supposed them 

 to ]iroduce similar effects to those brought about by testicular extracts. 



Fig. 9."). — Transverse .section 

 through uteius of I'at after 

 ovariotomy, siiowiiig degen- 

 erative changes. 



((;/'. Figs. 94 and 96. From 

 Marshall and -Tolly.) 



internal secretion is provided 



' Brown-Se<juard, "Des Etfets produits chez rHomme par des Injections, 

 etc," ('. It. de la Soc. de Biol, 1889. , 



