660 BURRILL B. CROHN 



secondary atrophy of the gland follow, does not necessarily create a se- 

 quential disturbance in absorption. 



Lombroso (a),, an Italian physiologist, offered some further valuable 

 evidence. After either simple tying off of the ducts, or after production of 

 an external pancreatic fistula (Pawlow) absorption of fats in dogs remains 

 normal (55.9 per cent to 84.3 per cent). If the atrophied remnant of 

 pancreas be now removed, fat excretion mounted rapidly to 40.4 per cent, 

 99.7 per cent and 113.5 per cent ! 



In another series of experiments Lombroso attempted to prove that a 

 fraction of the pancreas transplanted vicariously under the skin could pre- 

 serve good intestinal absorption. With the transplant viable and excreting 

 outwardly, absorption was only fairly well maintained, varying between 

 46 per cent and 77.4 per cent. Whenever the graft was well preserved, 

 absorption remained good. Upon removal of this transplant, the excretion 

 of fat in the stool rapidly increased to 96.6 per cent and 97.8 per cent; 

 nitrogen excretion varied similarly though not to so great a degree. 



Pfliiger directed criticism against these experiments in so far as he 

 pointed out that the persistence of good absorption in the presence of a 

 transplant could be due to vicarious excretion of digestive ferments into 

 the intestinal tract. 



Lombroso's contention was that it was an internal secretory function 

 of the gland and not the external secretion that maintained digestive effi- 

 ciency. (Compare von Mering and Minkowski(a) and Zunz and Mayer.) 



To establish this point he studied metabolism in a dog with an external 

 pancreatic (Pawlow) fistula, allowing the dog at times to lick the escap- 

 ing secretion, at other times muzzling the dog. No differences were seen 

 in comparing the two periods. 



Lombroso's experiments provoked much criticism. Hess(&) and also 

 Sinn pointed out that Lombroso had probably failed to tie all the ducts of 

 the dog and that in this way the partially preserved absorption was to be 

 accounted for. In one dog in which Hess (6) carefully tied all the ducts, 

 he noted a loss of 45.4 per cent nitrogen and 95.3 per cent of the ingested 

 fat. Lombroso's answer was that by his technic Hess had probably de- 

 stroyed the gland as well as tied the ducts. 



Burkhardt repeated Lombroso's experiments in an identical manner 

 and seemed to show that if the dog licked the secretion of the fistula in- 

 testinal absorption was retained at a high level; not so when the fistula 

 fluid drained away. 



To answer these criticisms Lombroso again repeated his experiments 

 and substantiated all the statements he had previously published. Lom- 

 broso^) further showed that not even by feeding to the dog large amounts 

 of duodenal contents from other healthy animals could he increase fat and 

 nitrogen absorption in his depancreatized dogs. 



Fleckseder, the same year, published a complete substantiation of Lorn- 



