458 HOMER WHEELON 



P 



duction in nervous activity of the gelding and steer is in part explained 

 by the actual alterations occurring in the nervous system following gonad- 

 ectomy. There is a constant diminution in the weight of the brains of 

 castrated rats, a condition in itself sufficient perhaps to account for dis- 

 positional and metabolic alterations. The writer has shown that gonad- 

 ectomy in adult dogs results in a constant and consistent lowering of the 

 systemic blood pressure reaction to standard doses of nicotin (Fig. 13). 

 Inasmuch as nicotin stimulates the vasomotor apparatus, it may be con- 

 cluded that castration results in a lowered irritability of the vasomotor 

 apparatus. If such nervous alterations result because of interstitial want, 

 the introduction of normal gonadal tissue should relieve- the depressed 



Fig. 13. Vasomotor reactions of dog to 1 c.c. of 1:2.000 solution of nicotin. a, 

 March 1, 11)15, before gonadectomy ; b, April 20, and c, May 1, 1915, after operation, 

 and d, May 23, 1915, 22 days after the reception of a testicular transplant placed May 

 1, 1915. Ether anesthesia.' (Wheelon and Shipley, 1916, Fig. 3, p. 398.) 



function, at least in part. As a matter of fact, the presence of testicular 

 transplants in dogs previously castrated is sufficient partially to reinstate 

 normal vasomotor irritability. Also, the grafting of testicular substance 

 into previously castrated animals and men is of great benefit in reestablish- 

 ing sexual powers, libido, and the masculine habits, although spermato- 

 genesis is not established (Lespinasse () (&), Lyclston, Morris (&), and 

 Lichtenstern). 



Somatic and nervous characteristics in animals carrying gonadal tissue 

 of the opposite sex develop, not according to the changes made during the 

 embryological period by reason of the gonads then present, but by reason 

 of gonadal factors derived from the implanted gland. For instance, 

 Steinach, Sand, and Moore have shown that castrated males into which 

 ovaries have been transplanted, develop nervous reflexes normally peculiar 

 to the female. These "feminized-males" show two female reflexes; the 

 tail erect reflex, and a 'kicking, guarding reflex to ward off the male before 

 the appearance of heat. Moreover, they are sought by normal males as 



