240 



FRANKLIN PARADISE JOHNSON 



caecum was considerably smaller than a normallj^ filled one, 

 it was by no means empty. The caecum and first part of the 

 ascending colon have greater diameters than the remaining 

 portions of the large intestine and their glands are shorter. In 

 table 2, because of the existence of large mucosal folds, the per- 

 imeters, measured at the bases of the glands, are given along 

 with the diameters. 



TABLE 2 



Measurements made from normally contracted pieces of large intestine of the guinea- 

 pig. Total length of large intestine about 72 cm. 



The pieces of intestine described in these tables perhaps do 

 not represent normally contracted intestine. They are emptied 

 portions of the intestine which are further contracted owing 

 to their immersion in Zenker's fluid. Whether or not under 

 normal conditions the intestine ever contracts to the same ex- 

 tent is a difficult problem to solve (owing to the introduction 

 of such factors as anesthesia, mechanical and chemical stimuli, 

 etc.), the determination of which seems not to fall under the 

 scope of the present work. It would perhaps be better, there- 

 fore, to use the term 'strongly contracted' in place of 'normally 

 contracted.' 



Normal distention 



A guinea-pig weighing 565 grams was killed under normal 

 feeding conditions. The stomach, caecum, and portions of 

 the small and large intestines (especially the ileum) were greatly 

 distended with food. Certain pieces of the intestine (2 to 3 

 cm. long) were tied off at both ends before removing, so as to 

 retain the intestinal contents and so that the walls could not 

 contract. An examination of cross and longitudhial sections 



