THE REGULATION OF GASTRIC SECRETION. 191 



in the pouch of its own accord, or may be fastened there by 

 an elastic band encircling the body of the animal. Juice is 

 collected while the animal is lying down or is supported in 

 an erect position in a suitable frame. 



It is only necessary to add that the miniature stomach 

 gives a true picture of the secretory activity of the large one 

 (F), even though food does not at all enter the small cavity. 

 This has been proved by a long series of carefully conducted 

 experiments, in which the quantity and quality of the juice 

 poured out in the large cavity has been compared with 

 that poured out in the isolated cul-de-sac. 



We have yet to describe an operative procedure which 

 is made use of in sham feeding, and upon which several 

 physiological facts concerning the stomach and its activity 

 are based. In 1889 PAWLOW and SCHUMOW-SIMANOWSKI 

 performed the operation of oesophagotomy on a dog already 

 possessing a simple gastric fistula. The oesophagus is 

 divided in the neck, and the divided ends are made to 

 heal separately into the angles of the skin incision. f This 

 separates the stomach and mouth entirely. Dogs operated 

 upon in this way recover and continue in excellent health 

 for years afterward. To keep such animals alive, food must, 

 of course, be introduced directly into the stomach. 



The following experiment shows how pure gastric juice 

 can be obtained from such an animal. If the dog be 

 given meat to eat, the food drops out again from the 

 lower extremity of the upper segment of the divided oasoph- 

 agus. But the perfectly empty stomach begins to secrete 

 gastric juice and this continues as long as the sham feeding 

 is kept up. As will be shown in detail later, this is a psychic 

 secretion of gastric juice. Suffice it for the time being to 

 state that several hundred cubic centimeters of pure gastric 

 juice may be obtained daily in this way without injury to 

 the dog. 



QEsophagotomy may be combined with the already de- 

 scribed operation of PAWLOW and CHIGIN for the separation 



