XX.—Unilateral Vasoligation on the Senile Male of the Domestic Fowl

Unilateral ligation of the vas deferens in the mammal is a method now commonly employed in the surgical treatment of senility. The demonstrably beneficial results that follow the operation are explained on the assumptions that the testis is an endocrine gland; that if the gametogenic function is embarrassed, the interstitial tissue, regarded as the source of the sex-hormone, undergoes hyperplasia; and that associated with this increase in amount of tissue there is an increased elaboration of the internal secretion.