374 INTERNAL SECRETIONS OF PANCREAS AND SPLEEN. 



juice of dogs of large breed Schiff generally found, even while 

 fasting, a certain quantity of trypsin; when the same were 

 spleenless, however, he was unahle to find any. 



"Digestion in the Normal Duodenum Provided with a Fist- 

 ula. A duodenal fistula was established in a dog. After com- 

 plete recovery a measured and constant quantity of albumin 

 was introduced every day into the duodenum inclosed in a 

 small envelope of fibrous membrane fixed to the cannula by a 

 thread some centimeters long. The progress of digestion was 

 then observed, the following results being obtained: 1. When 

 the animal was fasting the albumin took from 5 to 6 hours 

 to become dissolved. 2. When the albumin was introduced 

 into the duodenum during the 2 to 3 hours immediately fol- 

 lowing the ingestion of a meal by the animal it remained un- 

 changed. 3. When introduced 4 hours after a meal it dis- 

 appeared very quickly, in about half the time, in fact, occu- 

 pied during fast. These facts having been duly noted, the 

 spleen was' then extirpated, and after complete recovery the 

 same experiment was repeated; very different results were 

 now obtained. Whether fasting or in full digestion the time 

 taken for the digestion of the albumin was exactly the same, 

 viz.: from 5 to 6 hours. The acceleration in the peptonization 

 which had formerly appeared after the fourth hour of digestion, 

 and which coincided both with the appearance of trypsin in 

 the pancreatic juice and with the dilation of the spleen, was 

 now absent. The slow digestion (from 5 to 6 hours) in this 

 experiment was probably entirely due to the secretion of the 

 duodenal glands, which possess only a very feeble digestive 

 power; the active, rapid digestion was due to the appearance, 

 in large quantity, of trypsin in the pancreatic juice: a phe- 

 nomenon wanting in the spleenless animal. . . . Schiff 

 endeavored to interpret the facts by the following theory: 

 During the congestion of the spleen a substance is produced 

 within it which, carried away by the blood, gives to the pan- 

 creas the wherewithal to form its peptonizing ferment. . . . 

 In 1872, however, the theory of Schiff received a rude shock 

 through the great discovery of the zymogens by Heidenhain 

 and his pupils. From the researches of this observer it ap- 

 peared that, as the gastric mucous membrane forms at the 



