PHYSIOLOGY, CHEMISTEY AND PATHOLOGY 461 



pearance of puberty in man also is expressed by an increased vigor which 

 affects both physical and psychical activity. On the other hand, diminu- 

 tion of the functions of the genital glands (hormone) for any cause what- 

 ever, is accompanied by senile changes very similar to those resulting 

 from castration. Marked alterations occur in the cuticle and cuticular 

 glands, in the teeth, hair, and neuromuscular system of the aged. Gen- 

 eral senility also appears prematurely in eunuchs, although the teeth 

 usually remain white and solid. 



Alterations in Metabolism Affecting the Testes. In the testes of old 

 animals and senile men there is a marked and distinctive diminu- 

 tion of the interstitial cells, both in number and size. Evident signs of 

 atrophy are also present, as shown by the profusion of pigment in the cyto- 

 plasm and other enclosures. During acute diseases the interstitial cells 

 often become hypertrophied, but during long cachexia they too become 

 atrophic. In experimental intoxication and infection, the interstitial cells 

 hypertrophy at the beginning of the illness but finally become atrophied. 

 Such hypertrophy, according to Ancel and Bouin, Yoinov and von Hanse- 

 mann, is to be regarded as a protective measure on the part of the inter- 

 stitial glands. As a matter of common observation, hypertrophy and 

 hyperplasia of the interstitial cells are always accompaniments of both 

 imperfect development and secondary atrophy of the seminiferous tissue 

 Eccles, Hanes, Kuntz (&)). 



Marked alterations occur in the testes following prolonged stravation 

 and improper nourishment. According to Swingle, frog larvae starved 

 from the time of their emergence from the egg capsule over a period of 

 one hundred days do not grow or pass through the usual metamorphic 

 changes. Microscopic examination of the gonads show that these struc- 

 tures, like somatic development, have been completely inhibited. E. Allen 

 has shown that albino rats fed on a diet deficient in the water-soluble 

 vitamins are sterile; there is complete degeneration of the germ cells. 

 The sustentacular cells alone persist in the tubules, but these show marked 

 degrees of shrinkage of the nuclei. The interstitial tissue, on the other 

 hand, is hypertrophied, a condition analogous to the results following 

 exposure of the testes to the arrays. Similar results have been shown 

 by Portier to occur in the testes of pigeons fed on a devitaminized 

 diet, 



Influence of the Testes upon Bone Growth. The age at which genital 

 maturity takes place is of paramount influence in the growth of the skele- 

 ton. Late maturity, like genital hypoplasia, increases, height, especially 

 the length of the legs. Premature maturity results in the early closing 

 of the epiphyses and consequently shortening of the lower extremities 

 (Tandler and Gross). In cases of precocious puberty, pubertas precox 

 virilis, the acceleration of growth is accompanied by premature closing 

 of the epiphyseal synarthroses (Falta, Strauch, Neurath). Hypoplastic 



