94 PHYSIOLOGY OF THE PANCUEAS, 



111 a further papei-^'* Bayliss and Starling showed that secretin 

 from the pig, squirrel, new-born kitten, monkey, man, dog, cat, 

 frog, tortoise, sahnon, dog-fish, and skate, was acti\e upon the 

 dog. Also they showed that secretin produced an active flow of 

 pancreatic juice in the rabbit, cat, and monkey. They commented, 

 therefore, on the universality of the mechanism. They also 

 pointed out the probability of the chemical stimulus being the 

 active one in calling forth pancreatic juice during natural 

 digestion. 



Scope of investigation. — In this investigation the effect of 

 extracts of the mucous membrane of the intestine of numbers of 

 the Australian fauna has been tested, while incidentally a number 

 of observations on factors affecting the secretion was made. 



Methods, etc. — The animals used were dogs and native porcu- 

 pines (Echidna hystrix). Ether amiesthesia was used after 

 tracheotomy, the anaesthetic being given through a Wolff's bottle. 

 The dogs were previously narcotized with morphia hypodermically 

 administered. The blood pressure was recorded by a mercurial 

 manometer connected to the carotid artery. The pancreatic 

 juice was collected through a glass canula inserted into one of the 

 pancreatic ducts. The drops were noted with a watch and 

 marked by a lever on the recording cylinder. The extracts were 

 injected into the right jugular vein by means of a burette and 

 canula inserted into the central end of the vein, and controlled 

 by VjuU dog forceps. The extracts to be tested were prepared by 

 grinding the mucous membrane (either fresh or kept under 

 absolute alcohol) with sand. This mucosa was extracted with 

 from 2-5 times its weight of 0'4 % hydrochloric acid from 30 

 minutes to 16 hours. The extract was boiled, rendered fainth' 

 alkaline with soda, then just acid with acetic acid and filtered. 

 The filtrate was collected in sterile flasks, which were plugged 

 with wool while hot, and then boiled for five minutes. These 

 will keep sterile and active. If this is not done the extracts 

 putrefy, and the secretin disappears in from 5-10 days. In one 

 case a badly smelling extract made seven days before was filtered 



