460 METABOLISM, NUTRITION, AND DIET 



pend upon the loss of the pancreatic juice proper to the organism. This 

 secretion may be diverted from the intestine through a pancreatic fistula 

 without the production of diabetes. Moreover, Hedon and Thiroloix have 

 rendered the acini of the gland functionally inactive, and ultimately de- 

 stroyed them, by the injection of paraffin or other substances into the duct 

 of Wirsung, without the supervention of diabetes. 



These experiments have shown that the ordinary secreting cells degener- 

 ate and the islands of Langerhans increase in size, leading to the conclusion 

 that the islands are the structures that produce a special internal secretion 

 which influences or controls carbohydrate metabolism in the body. When 

 the dextrose cannot be readily burned in the body, the content of this sub- 

 stance in the blood is increased and this excess is eliminated by the kidneys. 

 Products of incomplete oxidation of the sugar are also thrown into the circu- 

 lation and eliminated into the urine. In diabetic cases oxybutyric acid, 

 aceto- acetic acid, acetone, etc., are found in the blood and urine. Neither 

 pancreatic nor muscle extracts have the power of burning sugar. Conheim, 

 however, showed that when extracts of the pancreas and of muscle were 

 brought together, the resulting mixture would destroy the dextrose added to 

 it. This interaction of pancreas and muscle, then, offers an explanation 

 of the perverted carbohydrate metabolism after removing or in pathological 

 conditions of the pancreas. 



The Reproductive Glands. The ovary and the testes are undoubt- 

 edly concerned with metabolism in the body. It has been shown repeatedly 

 that extracts of the testes when injected into the system lead to increased vigor 

 both of the muscular and of the nervous systems. Ergograms show an 

 increase in muscular power. Spermin isolated from the testes is claimed 

 by its discoverer to produce the beneficial effects described. The removal 

 of the testes in domestic animals is followed by an entire change in the 

 character of the development of the animal, especially in the so-called second- 

 ary sexual characters. Such animals show less vigor and less muscular power. 



The removal of the ovaries in women, through surgical operation, has 

 resulted in very marked nervous symptoms. These symptoms are reduced 

 or entirely disappear on grafting a portion of the gland, and the disturbed 

 menstruation following ovariotomy becomes regular again. Experiments 

 by Loewy and Richter indicate that oxidations in the body are greatly in- 

 creased on feeding ovarian extract to ovariotomized animals. 



There are other organs whose function is still obscure but in which 

 the indirect evidence points to an influence on metabolism at one stage or 

 another of the existence of the animal body. Enough has been given here 

 to show that the interrelation of the organs is extremely complex in so far as 

 the metabolism is concerned. It is not enough simply to know the foods and 

 their composition. The whole complex of intermediary metabolisms and 

 their influences must constantly be taken into consideration. 



