DIGESTION. 1Q7 



shows that pancreatic growth is a function of the islet-tissue cell, 

 multiplication being observed only in the islet. As the islets are 

 formed from the alveoli, there must be a constant disappearance of 

 islets and a new formation of the alveoli. 



In pancreatic diabetes the proportion of dextrose to nitrogen 

 (D : N) excreted in starvation is 3 to 1. In this kind of diabetes, 

 the sugar is derived from the glycogen; and when the glycogen is 

 used up, it, like the nitrogen, comes from the proteid. In ordinary 

 states, after the removal of the pancreas the sugar comes from the 

 dextrose in the food, and from the proteid of the food and of the 

 tissues. The cause of accumulation of sugar in hyperglycaemia is 

 the removal from the organism of some influence necessary to oxidize 

 the dextrose. Lasvulose can still be oxidized and also form glycogen. 



Continued Action of Trypsin. 



The proteid molecule is more thoroughly broken up by trypsin 

 when it has been previously acted upon by pepsin, than when attacked 

 by trypsin alone. When the action of trypsin is continued for a long 

 time, it acts like an acid, hydrolyzing the proteid product and form- 

 ing mainly amino-acids, that is, organic acids containing one or more 

 amido groups in direct union with carbon. The amido-acids are 

 chiefly as follows : 



1. MONO-AMINO ACIDS. Glycocoll, alanin or amino-propionic 

 acid, phenyl alanin, amino-butyric acid, and leucin, which crystallizes 

 in the form of spheroidal crystals. 



Leucin (C 6 H 13 N0 2 ) is an a-amido-isobutylacetic acid, belonging 

 to the fatty acid series. It is always formed in any profound decom- 

 position of proteid, such as boiling with dilute acids, or alkalies, in 

 tryptic digestion, or putrefaction. It has been found in nearly every 

 tissue of the body in some proportion, being particularly common in 

 pathological conditions of the tissues. It may be produced syntheti- 

 cally in the chemical laboratory. 



(a) The mono-amins of dibasic acids: Aspartic acid, gluta- 

 minic acids. 



2. THE DIAMINO ACIDS. The so-called hexone bases, arginin, 

 lysin, histidin. 



Arginin is a product of hydrolysis of all proteids, being the 

 most abundant of the basic substances. It is especially found in the 

 proteid of certain seeds and in the protamins. Salmin, a protamin 

 of the spermatozoa of salmon, contains 80 per cent, of arginin. This 



