41 THE WORK OF THE DIGESTIVE GLANDS. 



remoulding of the pancreas takes place in the slowest manner. In such 

 cases as the latter, an abrupt transition from one regime to a different 

 one can often produce serious illness. 



Dealing now with the gastric glands, the question of lasting altera- 

 tions in ferment production must be left unanswered. We have up to 

 the present obtained gastric juice in the laboratory from a very large 

 number of dogs (twenty to thirty) by means of the sham feeding, but, 

 notwithstanding, have never seen any striking or constant differences 

 in the digestive power of the juice obtained from the dogs. Towards 

 solving this problem Dr. Samojloff" (in experiments not yet published) 

 has made observations on three gastro- and oesophagotomised dogs. 

 The dogs were tested beforehand by oft-repeated sham feeding ex- 

 periments and then placed on different diets. After a considerable 

 time they were again tested with the sham feeding, but the gastric 

 juice showed no essential divergence from that previously obtained. 

 How are we to interpret these results ? Are our methods of estimating 

 the ferment content of the gastric juice defective, or do the gastric and 

 pancreatic glands differ in this important respect ? It is, of course, 

 possible that the pancreas plays the role of a supplementary, so to speak, 

 reserve gland, whose duty is now augmented, now diminished, in 

 accordance with the burden of work placed upon the digestive canal, 

 while the gastric glands, as the first important digestive agency, must 

 always work at maximum pitch. A fact not easy of interpretation, how- 

 ever, has recently been observed in our laboratory by Dr. Lobassoft', which 

 possibly indicates that lasting alteratioi^s of the gastric glands may 

 appear under the influence of prolonged dietetic conditions. We have 

 in our possession a dog with a portion of the fundus of the stomach 

 isolated according to the method of Heidenhain that is to say, involving 

 division of the vagi. I ought to add that, when such dogs live for a 

 length of time after the operation, the secretion of gastric juice becomes 

 gradually less and less (observation of this laboratory). The dog in 

 question presented the following condition : When it had been fed 

 freely every day on flesh for a considerable period of time, a certain 

 test meal always yielded a much greater secretion than when the animal 

 had been fed upon other foods, such as oatmeal porridge, &c. Since, how- 

 ever, in a dog thus operated upon, the gastric glands live and work under 

 altered conditions, too great stress cannot be laid upon this instance. 



All the facts given accord sufficiently with our previous conclusion, 

 which may be once more repeated namely, that the work of the 

 digestive glands so far investigated is unusually complex and elastic, 

 but at the same time astonishingly exact and purposive. It is true we 

 have only encountered the latter property v.-ith unquestioned distinctness, 

 up to the present, in a small number of cases. 



