AUTO LYSIS. 193 



the cleavage of fats into glycerin and fatty acids, which are then 

 absorbed and reconstructed into neutral fats by the intracellular 

 lipase, in consequence of the reversible action of which this is ca- 

 pable (Kastle and Loevenhart). 



The digestion of fats is facilitated by the presence of bile. This 

 is apparent from experiments in which the bile was prevented from 

 entering the intestinal tract, when it could be demonstrated that 

 only the seventh part to one-half of the fat was resorbed, while the 

 remainder, principally in the form of fatty acids, appeared in the 

 feces. The former view, according to which the bile facilitates the 

 emulsification of the fats and renders the intestinal wall more 

 permeable, does not express the actual function of the bile in 

 this respect. Moore, Rockwood, and notably Pflliger have shown 

 that its principal import in this direction is referable to the readi- 

 ness with which it dissolves soaps, and through their aid also free 

 fatty acids, especially oleic acid, which in turn dissolves stearic acid 

 and palmitic acid. 



The lecithins, like the fats, are decomposed by steapsin into their 

 components, viz., into glycerin-phosphoric acid, the corresponding 

 fatty acids, and cholin. The former is then absorbed, and appears 

 in part at least in the urine as such. The fatty acids after saponifi- 

 cation are similarly absorbed and reconstructed into neutral fats, 

 while cholin is decomposed by the bacteria which are present in 

 the intestines, with the formation of carbon dioxide, methane, and 

 ammonia. 



AUTOLYSIS. 



By autolysis is meant the self-digestion of tissues in the absence 

 of micro-organisms. The phenomenon is referable to the action of 

 intracellular ferments, and is of universal occurrence both in the 

 animal and the vegetable world. The changes which occur are 

 essentially postmortem changes ; but it is possible that something 

 similar occurs during life. 



As I have already pointed out, the ferments in question are more 

 or less specific in their action, and albumins which are foreign to a 

 certain cell are, generally speaking, attacked with greater difficulty 

 by the autolytic ferments of that cell than the albumins of homol- 

 ogous cells. The proteolytic ferments of hepatic tissue thus attack 

 the albumins of lung-tissue only very slowly. 



The proteolysis proceeds as in the case of the digestive ferments 

 and the end-products are the same. In the case of the pancreas 

 the following products have been obtained : ammonia, leucin, tyro- 

 sin, aspartic acid, glutaminic acid, arginin, lysin, histidin, cadaverin, 

 oxy-phenyl-ethylamin, skatosin, uracil, guanin, adenin, xanthin, 

 hypoxanthin, cholin, etc. Especially interesting is the formation 

 of oxy-phenyl-ethylamin, which is derived from tyrosin through 

 loss of CO 2 , as it demonstrates the possibility of a fermentative 



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