INTERNAL SECRETIONS OF SEXUAL GLANDS 93 



But what is stated about the results of feeding with sexual 

 glands is very contradictory, especially in therapeutical ex- 

 periments where different pharmaceutical preparations were 

 administered. We shall restrict ourselves here to giving an 

 example of one successful and one unsuccessful experiment . The 

 first was made by ^. Loewy (1903, pp. 138-40) on capons which 

 were fed with testes. Loewy relates that the head apparel 

 developed better than in control capons. He mentions also an 

 effect on the skeleton in which all the changes characteristic of 

 the "castrate" were prevented when young capons were fed 

 with testes. Steinach (1910) fed rats castrated at an age of four 

 weeks with fresh testes of adult rats, guinea pigs and rabbits. 

 Although the feeding experiment lasted more than three 

 months the animals remained typical "castrates," and not the 

 smallest effect could be observed. 



The negative result does not however imply that feeding 

 with testis or with ovary must necessarily always be negative 

 in its results with mammals. On the other hand there can 

 scarcely be any doubt that the metabolism of mammals may 

 be changed in one or other direction by feeding with ovary or 

 its preparations. This is in accordance with Loewy' s ex- 

 periment mentioned above and with numerous experiments 

 performed lately by many investigators on tadpoles for different 

 purposes. In my Institute Wagner (1922) found that the 

 metamorphosis of tadpoles, retarded by late artificial fecun- 

 dation, can be accelerated by feeding with ovary. But no 

 specific influence through feeding with testis or ovary has 

 ever been observed, i.e., the formative influence which the 

 testicle or the ovary exerts on the sex characters in the body 

 could not be replaced by feeding upon these organs. 



C. INJECTION. 



As with the feeding experiments injection experiments with 

 testis or ovary on mammals have given very contradictory re- 

 sults. It suffices to mention the experiments of Brown-Sequard 

 (1889) ^^^<^ others upon man. New experiments of this kind 

 have been recently performed by Stanley (1921), who made 

 numerous injections in over 300 cases. He used aseptically 

 prepared material from ram, goat or boar a year to eighteen 

 months old, i.e., from animals which had reached sexual 

 maturity. The injections were made subcutaneously on the 



