212 PHYSIOLOGICAL CHEMISTRY. 



consumption of the inner granular zone, while the outer zone at the 

 same time took up new material and became larger. In these stages 

 the quantity of zymogen is smallest. At a later period, 12-20 hours 

 after a meal, the inner zone is re-formed from the outer, and the 

 larger this zone is the larger the quantity of zymogen in the gland 

 seems to be. The zymogen consequently belongs to the inner zone, 

 and the secretion consists therefore, at least in part, in a destruc- 

 tion or dissolution of this zone whereby the substance of the gland 

 itself is changed into the secretion (HEIDENHAIN). This view, 

 however, is in opposition to that of LEWASCHEW, who observed 

 that in animals which have starved and whose pancreas-glands are 

 nearly free from zymogen, the inner granular zone is just as much 

 developed as under normal conditions and contains abundant quan- 

 tities of zymogen. We are still completely in the dark regarding 

 the nature of the chemical processes which take place in the con- 

 version of the zymogen into the enzyme. 



V. The Chemical Processes in the Intestine. 



The action which belongs to each digestive secretion may be 

 essentially changed by mixing with other digestive fluids; and since 

 the digestive fluids which flow into the intestine are mixed with 

 still another fluid, the bile, it will be readily understood that the 

 combined action of all these fluids in the intestine makes the 

 chemical processes going on therein very complicated. 



As the acid of the gastric juice acts destructively on ptyalin, this 

 enzyme has no further diastatic action, even after the acid of the 

 gastric juice has been neutralized in the intestine. The bile has, at 

 least in certain animals, a faint diastatic action which in itself can 

 hardly be of any great importance, but which shows that the bile 

 has not a preventive but rather a beneficial influence on the 

 energetic diastatic action of the pancreatic juice and the faint 

 diastatic action of the intestinal juices. MAKTIK and WILLIAMS 

 observed, in experiments made recently, a beneficial action of the 

 bile on the diastatic action of the pancreas infusion. To this may 

 be added that the organized ferments which occur habitually in 

 the intestine and sometimes in the food have partly a diastatic 



