380 INTERNAL SECRETION 



scanty. Roberts's observations in India have little value in this 

 connection, for the operation in his cases consisted in mutilation 

 of the external genitals only. It is known from the results of 

 experiments with animals (Hegar, Kehrer), that if both ovaries 

 are removed from female animals which have not reached sexual 

 maturity, the development of the entire genital apparatus will be 

 retarded, the uterus and Fallopian tubes remaining rudimentary. 

 By transplanting the extirpated ovaries under the skin, Halban 

 effected perfect development of the sexual apparatus, thus proving 

 that the protective influence of the ovaries is effected, not by 

 means of trophic nerves, but by the agency of an internal secre- 

 tion. 



Castration is frequently performed on women who have 

 passed the age of puberty. It is common knowledge that this 

 operation is followed by regressive changes in the secondary 

 genitals, shrivelling and atrophy of the uterus and vagina being 

 invariable findings. This atrophy was formerly explained by the 

 suppression of a trophic nerve centre supposed to be present in 

 the ovary. But Knauer's experiments have shown that, if the 

 ovaries are removed from their place and implanted in another 

 part of the body, atrophy of the uterus will not take place. Fur- 

 ther experiment (Ribbert, Grigorieff, Rubinstein, Herlitzka, 

 Marshall and Jolly, Carmichael and Marshall, Daels, &c.) next 

 showed that the presence of even a portion of one ovary in any 

 part of the body is sufficient to maintain the complete anatomical 

 integrity and functional activity of the genital organs. Preg- 

 nancy may even occur after intraperitoneal transplantation of the 

 ovaries, and this result is a measure of the success which may be 

 obtained by ovarian transplantation in women. 



The implantation of ovaries from animals of another species 

 has been repeatedly performed with successful results (Schultz, 

 Katsch, Carmichael and Marshall, Bucura). These ovaries (for 

 instance, those of the guinea-pig in a castrated rabbit, Bucura) 

 not only heal in but remain functionally active, for their follicles 

 become mature and atrophy of the uterus does not take place. 

 The implantation of testes into a female animal succeeds to this 

 extent, that the spermatogenetic tissue elements of the implanted 

 organs remain intact and spermatozoa may even be produced, but 

 the presence of the male genital gland does not prevent uterine 

 atrophy. The implanted testicle does, however, exercise a certain 

 influence upon the metabolism of the castrated female, the increase 

 in the weight of the body being considerably less in these cases 

 than after simple castration. 



The subcutaneous injection of ovarian extract, whether from 

 the same or another species, does not prevent uterine atrophy 

 after castration (Jentzner and Beuthner). Bucura found that the 

 injection of ovarin into castrated animals was followed, not only 

 by atrophy of the muscles of the uterus, but by an increased dis- 



