Digestion. 131 



circumstance, and probably connected with the function of 

 rumination. The contents of the stomach are alkaline, except- 

 ing in calves fed on milk, and consist of food only roughly 

 comminuted, containing an amount of fluid which plays an 

 important part in rumination, and which is derived from 

 the fluid consumed, mixed with enormous quantities of 

 saliva. This stomach communicates with the oesophagus 

 and the reticulum. 



The Reticulum is arranged like a honey-comb ; it is a 

 very small stomach, and its contents are normally fluid 

 and alkaline. In the pouches formed by the reticulated 

 arrangement foreign bodies are commonly found, and when 

 they penetrate the heart it is from here that they pass into 

 the chest. 



The use of the reticulum is to contain fluid; so that 

 the openings leading from this stomach into the cavities 

 of the first and third are considerably above the base of the 

 viscus. This fluid is used during rumination, and is [forced 

 into the oesophagus by muscular contractions. In reaction 

 the second stomach is alkaline, and it possesses no secretion 

 from its walls. 



The muscular coats of the stomachs vary in thickness. 

 The rumen is comparatively thin, the reticulum thick. By 

 means of the muscular tissue the food is submitted to a 

 constant churning motion, which continually revolves the 

 contents. This process in the rumen is one of considerable 

 importance, as it brings the food towards the opening of 

 the oesophagus for the purpose of rumination, The process 

 is slow and deliberate, the material at the posterior portion 

 of the rumen being gradually forced ■ forward and upward, 

 and made to revolve within the cavity. 



Solid material, no doubt, enters the rumen and reticulum 

 tirst, but liquids may enter all four stomachs at one and 

 the same time ; this has been proved by the investigations 

 of Flourens. It is probable that the greater part of the 

 fluid drunk passes direct to the rumen and reticulum, for it 

 is certain that the presence of fluid in these stomachs is 

 absolutely essential to rumination. 



9—2 



