RUMINATION. 59 



the food fails to float loosely in the liquid, and becomes 

 aggregated in a firm, unbroken mass, rumination becomes 

 impossible. 



"If we watch the ox ruminating it will be seen that 

 when a cud is brought up, the act is immediately followed 

 * by a swallowing of liquid, after which the animal begins 

 leisurely to chew the solid matters. These loose solids are 

 floated up in a quantity of liquid, both having flowed into 

 the demi- canal during the compression of the stomach, 

 and been returned to the mouth by the contraction of this 

 canal and of the gullet in a direction from below upward. 

 On reaching the mouth the solids are seized between the 

 tongue and palate, and the liquids returned. If the con- 

 tents of the rumen are accumulated in firm masses, with 

 no detached floating material, it is manifest that liquid 

 only could be brought up. If, on the other hand, the 

 liquids present are only sufficient to impregnate these 

 masses without floating them, nothing whatever can be 

 brought up. Like the sheep of Flourens, the subject 

 ceases to ruminate. Colin demonstrated this use of the 

 liquid by placing four stitches at the opening of the demi- 

 canal, so as to prevent the entrance of pellets, or of any- 

 thing but fluids and finely disintegrated solids. Yet the 

 subjects continued to chew the cud as before. 



"During rumination the already softened aliments are 

 still more perfectly broken down by the teeth, and mixed 

 with a new secretion of saliva, and are thus better pre- 

 pared for a continuance of the chemical and mechanical 

 changes which they have already been undergoing in the 

 paunch. 



"It has not been clearly made out to what stomach food 

 is returned after rumination. But it may be fairly inferred 

 that like finely divided soft food, after the first mastication, 

 it passes in varying proportions into all four stomachs. 

 What returns to the first two, is no doubt returned in part 



