322 INTERNAL SECRETIONS 



B. EXTRACTS OF DIFFERENT PARTS OF THE 

 SEX GLAND. 



The question as to the effects of extracts of the sex gland 

 becomes still more complicated if we take into consideration 

 the probability that different parts of the testicle and of the 

 ovary are involved in the endocrine functions of these organs 

 in different ways, as we have seen already in Chapters IV. 

 and V. Many experiments have been made dealing with this 

 problem. In Chapter III. we have discussed similar experi- 

 ments by Bouin and Ancel on the guinea pig, and by Pezard 

 on the cock. In these experiments crypt orchid testicles 

 have been employed for the preparation of extracts. Since 

 all the higher stages of spermatic cells were absent in these 

 testicles, as shown by histological examination, the experi- 

 ments give further support to the assurhption that the produc- 

 tion of sexual hormones is possible without maturation of the 

 generative part taking place. The negative results obtained 

 by Bamabo (quoted from Harms, 1922), who, in experiments 

 similar to those of Bouin and Ancel, used extracts prepared 

 from testicles after resection of the vas deferens, do not nullify 

 this conclusion, since they may quite easily have been due to 

 the mode of preparation of the extract. 



The experiments of Pezard are of especial interest also in 

 another respect. Since the growth of the comb and of the 

 wattles in the capon can be promoted by injecting an extract 

 prepared from the retained testicle of the pig, it is shown by 

 these experients that the sexual hormones are not specific for 

 each kind of animal. There is a "sex specifity," but not a 

 specifity for the particular species. 



The question as to the effects of extracts prepared from 

 different parts of the ovary has attracted much more interest 

 on account of the great practical significance of these problems 

 in gynaecology. As far as I know the first experiments with 

 injection of corpus luteum were those performed by Fraenkel 

 (1903, p. 491; 1910, p. 753). This investigator introduced 

 these extracts into medical practice in the form of tablets 

 prepared from the corpus luteum of the cow. Similar experi- 

 ments have been made by several others. We need not 

 discuss here the many details concerning the use and the 

 results of this treatment in gynaecological practice, but the 



