66 



Though the contractions of tlie isolated piece of intestine cannot 

 be considered identical with the movements taking place in the 

 body in normal circumstances, yet it must be assumed that certain 

 properties of the living intestine may be studied by means of the 

 isolated one. 



The results obtained with the 2 kinds of animals mentioned last, 

 are not absolutely certain, as we were not able to study for a long 

 time at a stretch the intestinal movements of these animals, which 

 were killed at tlie slaughter-house. This was only the case with those 

 which were killed at the laboratory. 



Perhaps it is more difTicnlt to feed the thick- walled intestines of 

 pig and cow sufficiently with O.^. Moreover the intestines of the 

 animals killed, cannot be exposed at once to a current of oxygen, 

 because the intestines have to be taken from the slaughter house 

 to the laboratory. This was done as carefully as possible in a 

 so-called Thermos-tlask (Dewar's flask) which had been filled with 

 a Tyrode solution of 37° saturated with 0^. Thus we were enabled 

 to prevent the intestine from being cooled down. 



As a rule the movements of the duodenum are somewhat more 

 rapid than those of the ileum. Here, however, we shall give only 

 the average values; the extreme values are not absolutely certain. 



I. Intestinal movements of various species of animals: at ca. 36.5° 



II. After the preceding remarks (effect of the size of an animal) 

 it was not impossible that the age of the animal might affect the 

 velocity of the intestinal mo^^ements. It might be expected then that 

 the intestines of a young animal would move more rapidly than 

 those of an older animal of the same kind. 



The result of these experiments is that only the intestines of the 

 very youngest animals of some species move somewhat more rapidly. 

 A rabbit of 88 grammes for instance (3 days old) had J 6 — 18 intestinal 

 moN ements a minute. A rabbit of 235 grammes (3 weeks old) had 14 



