216 A MANUAL OF VETERINARY PHYSIOLOGY 



may pass its contents practically direct into the colon, and the 

 slightly funnel-shaped arrangement of the latter would readily 

 admit the rigid nozzle of the ileum. 



The contents of the caecum are always fluid, sometimes quite 

 watery, occasionally of the colour and consistence of pea-soup, 

 in which condition they are full of gas bubbles ; when watery, the 

 fluid is generally brownish in colour, with particles of ingesta 

 floating about in it. The reaction of the contents is always 

 alkaline ; all observers are agreed on this point.* 



The caecum is most admirably arranged as a receptacle for 

 fluids, and though absorption undoubtedly occurs from it, and 



Fig. 75. — The Opening of the Ileum and Colon in the Cecum. 



1, The ileum ; 2, the colon. In the figure the openings are represented close 

 together, but even when stretched apart they are less than 4 inches distant. 



digestion of cellulose takes place in it, yet we believe its chief 

 function is the storing up of water for the wants of the body and 

 the digestive requirements, as it is absolutely certain that 

 digestion in the horse can only be properly carried out when the 

 contents are kept in a fairly fluid condition. We do not say that 

 the caecum produces no digestive changes in the food, for we have 

 stated that the contents are occasionally of the consistence of 

 pea-soup, but we consider its digestive function subordinate to 

 its water-holding one. Ellenberger views the caecum as a bowel 

 for the digestion of cellulose, where by churning, maceration, and 

 decomposition, this substance is dissolved and rendered fit for 

 * The -writer only once found the caecum acid. 



