274 AN AMERICAN TEXT-BOOK OF PHYSIOLOGY. 



of ergographic records, of the stimulating action of the testicular extracts 

 upon the neuro-muscular apparatus in num. They find that injections of the 

 testicular extracts cause not only a diminution in the muscular and nervous 

 fatigue resulting from muscular work, but also lessen the subjective fatigue 

 sensations. The fact that the internal secretion of the testis, if it exists at 

 all, is not absolutely essential to the life of the body as a whole, as in the 

 case «>t' the thyroids, adrenals, and pancreas, naturally makes the satisfactory 

 determination of its existence and action a more difficult task. 



Similar ideas in general prevail as to the possibility of the ovaries furnish- 

 ing an internal secretion that plays an important part in general nutrition. 

 In gynecological practice it has been observed that complete ovariotomy 

 with its resulting premature menopause is often followed by distressing 

 symptoms, mental and physical. In such cases many observers have reported 

 that these symptoms may be alleviated by the use of ovarian extracts. So 

 also in the natural, as well as in the premature menopause following opera- 

 tions, it is a frequent, though not invariable, result for the individual to gain 

 noticeably in weight. The probability of an effect of the ovaries on general 

 nutrition is indicated also by the interesting fact that in eases of osteomalacia, 

 a disease characterized by softening of the bones, removal of the ovaries may 

 exert a very favorable influence upon the course of the disease. These indi- 

 cations have found some experimental verification recently in a research by 

 Loewy and Richter 1 made upon dogs. These observers found that complete 

 removal of the ovaries, although at first apparently without effect, resulted 

 in the course of two to three months in a marked diminution in the consump- 

 tion of oxygen by the animal, measured per kilo, of body-weight. If now the 

 animal in this condition was given ovarian extracts (oophorin tablets) the 

 amount of oxygen consumed was not only brought to its former normal, but 

 considerably increased beyond it. A similar result was obtained when the 

 extracts were used upon castrated males. The authors believe that their 

 experiments show that the ovaries form a specific substance which is capable 

 of increasing the oxidation of the body. 



Kidney. — Tiegerstedt and Bergman 2 state that a substance may be 

 extracted from the kidneys of rabbits which when injected into the body of 

 a living animal causes a rise of blood-pressure. They get the same effect from 

 the blood of the renal vein. They conclude, therefore, that a substance, for 

 which they suggest the name " rennin," is normally secreted by the kidney 

 into the renal blood, and that this substance causes a vaso-constriction. 



l Archivfiir Physiologie, 1899, Buppl. Bd. S. 174. 



2 Skandinavisehes Archiv far Physiologie, 1898, Bd. viii. S. 223; see also Bradford: Proceedings 

 of the Royal Society, 1892. 



