150 A Manual of Veterinary Physiology. 



Unless cellulose performs some more important function 

 than that of yielding sugar, it is difficult to conceive that 

 such enormous and elaborate bowels should exist for its 

 digestion. We are even ignorant of the means whereby 

 it undergoes digestion. A cellulose ferment, such as that 

 found by BroAvn in oats and barley (p. 12!)), is probably the 

 explanation, but such has not yet been found in hay, or 

 the digestion may occur under the influence of intestinal 

 organisms. Bunge imagines that the epithelial cells of the 

 intestine dissolve cellulose as well as convert dextrin into 

 sugar. 



We have previously (p. 16) mentioned Bunge's views on 

 the value of cellulose in a diet. He considers that it is 

 absolutely essential to animals with a long intestine, as it 

 acts as a natural stimulus to the bowel, and promotes 

 peristalsis. 



In the single colon we have noted the remarkable and 

 sudden change of highly fluid, thick, soup-like ingesta, 

 into comparatively dry feces. As the material moves 

 towards the anus it becomes drier and drier, and more 

 thoroughly formed into balls by the action of the bowel- 

 sacs, which squeeze the mass into a round or oval shape. 

 The contents of this portion are still alkaline, or slightly so, 

 though as we approach the rectum a distinctly acid reaction 

 is obtained on the surface of the fauces, though at this time 

 the interior of the ball may be, and often is, alkaline ; the 

 converse of this may also be obtained. In the rectum the 

 single balls collect in masses, to be forced out of the body 

 at the next evacuation. The reaction of this mass is acid, 

 the colour depending on the food, but having rather a 

 reddish-yellow or brownish tint on ordinary diet. 



Absorption from the single colon and rectum is very 

 rapid. Animals may be killed by the rectal injection of 

 strychnine, or life may bo supported by nutritive enemata. 

 Narcosis can also be produced by the rectal administration 

 of ether. 



Putrefactive Processes in the Intestinal Canal. — We may 

 here consider the nature of the putrefactive processes 



