INTERNAL SECRETIONS OF SEXUAL GLANDS 95 



is a very complicated one, since it is influenced by many factors 

 such as the skeleton, muscles, internal organs and fat deposit. 

 In male rabbits I found no difference between the weight of 

 normal and castrated animals in the first six months after birth, 

 or about four months after castration, whereas later on I found 

 a striking difference, the "castrate" attaining a greater weight. 

 This seems to be due especially, as already said, to the accumu- 

 lation of fat. 



Pezard's experiment (1911) was performed on a cockerel 

 castrated two months before and showing signs of castration. 

 Intraperitoneal injections of an extract of retained pig testicle 

 were made twice a week for about five months. The comb of 

 the injected bird got longer than in the control which was an 

 ordinary "castrate." The entire head apparel underwent 

 development, became rich in blood, and capable of erection. 

 When the injections were stopped the comb decreased in length, 

 and about 2^ months later was of the same length as in the 

 uninjected control "castrate." The whole of the head apparel 

 also became pale. Pezard relates also that sexual instincts 

 were shown by the injected bird which crowed and fought with 

 other birds. The sexual instincts disappeared and the 

 crowing ceased when the injections were stopped. The 

 body weight of the castrated bird was not changed by the 

 injections. 



Experiments have been made on the frog by several in- 

 vestigators. Nussbmim (1909, p. 554) inserted the testicles 

 into the Ijmiphatic sacs in a number of castrated frogs ; the pads 

 and the vesiculae seminaJes grew, although the testicles gradu- 

 ally degenerated. In order to bring about a successful result 

 it is necessary to place a new portion of testicle into the lym- 

 phatic sac before the previous portion has entirely degenerated. 

 Castration effects can be prevented also by repeated injections 

 into the lymphatic sac with a pulp made of testicle. A great 

 number of similar experiments were made by Steinach (1910), 

 who studied the dependence of the clasp reflex upon the testicle. 

 Having castrated the frogs and found by repeated testings 

 that the reflex could no longer be evoked, he injected into the 

 dorsal Ijmiph sac a pulp of testicular substance taken from 

 frogs "in heat." About 12 to 24 hours later the clasp reflex 

 appeared; in some cases it began gradually. In about two 

 days the maximum was reached and the reflex disappeared 



