INTERNAL SECRETIONS OF SEXUAL GLANDS 97 



D. INTERNAL SECRETION OF THE SEX GLANDS 

 AND NERVOUS SYSTEM. 



I. Is THERE AN ACCUMULATION OF THE INTERNAL SECRETION 



IN THE Central Nervous System ? 



We have seen that the nervous system is erotized by an 

 internal secretion of the sexual glands in such a manner that 

 the psycho-sexual reflexes are rendered possible, and further 

 that this erotizing action is caused by hormones The question 

 next arises as to whether this action is an elective one similar 

 to that of certain well known chemical poisons. Such an elective 

 action could be proved, if one could demonstrate that erotizing 

 substances secreted by the sex gland are accumulated in the 

 central nervous system. Steinach relates having observed 

 such an accumulation. He injected into a series of castrated 

 frogs extract of brain and spinal cord from frogs on heat, and 

 into a second series of castrated frogs brain and spinal cord 

 of "castrates" were injected. In the first series a good clasp 

 reflex appeared, in the second series no changes were visible. 

 On the other hand Steinach claims to have shown, as already 

 mentioned, that injections of other organs of frogs in heat are 

 unable to evoke the clasp reflex in a "castrate." These ex- 

 periments seem to show that there is an elective action of 

 substances secreted by the testicle upon the central nervous 

 system, due to an accumulation like that of strychnine; but 

 the subject requires a more detailed experimental investigation. 



It has also been claimed that the central nervous system acts 

 as a mediator between the sex glands and the organs influenced 

 by the internal secretion during heat. This question was 

 investigated by Nussbaum (quoted from Pfluger, 1907) ex- 

 perimentally. He severed the nerve of the forearm of the 

 frog on one side just at the time when the pads begin to 

 hypertrophy. The development of the pad did not take place 

 on the operated side. Nussbaum concluded from this obser- 

 vation that the internal secretion of the testicle acts in a specific 

 manner only on certain nervous centres from which impulses 

 are sent to certain organs, and the metabolism of the latter is 

 changed in a given direction. A similar view was held by 

 Steinach, who pointed out that the primary action of the 

 internal secretion would be that on the central nervous system. 



