CLASS MAMMALIA. 



217 



FIG. 377. 



open the channels, so apt to become filled with the lux- 

 uriant growth of that tropical region. 



The remaining Ungulates (ung'gu latz), from the fact 

 that they chew the cud, are called Ruminants. As these 

 animals are largely preyed upon by carnivorous animals, 

 and as mastication is a work of time, they fill a large 

 stomach-reservoir by rapid grazing, re-chewing its con- 

 tents in a place of security. The stomach is divided into 

 four compartments. The food 

 passes without mastication in- 

 to the rumen (roo'men) [p], 

 next into the reticulum (re- 

 tik'u lum) [b], thence back 

 through the oesophagus (e sof- 

 a gus> [o] to the mouth, where 

 it is masticated ; then down 

 the oesophagus a second time 

 into the leaflet [/], and thence 

 into the caillette (ki'yet) [c], 

 or true stomach. The mech- 

 anism by which the food goes 

 through the same orifice at the bottom of the oesophagus, 

 at one time into the rumen and at another into the 

 leaflet, may well create surprise. The oesophagus is con- 

 tinued below in a tube [c a], with a slit on the under 

 side whose lip-like edges shut water-tight, forming a pas- 

 sage from the oesophagus to the leaflet. If, however, the 

 mouthful of food swallowed be large and solid, as it is 

 when first eaten, it distends the tube, and, separating the 

 edges of the slit, falls into the first stomach ; but if it 

 be soft and pulpy, as it is after being re-chewed, it does 

 not force apart the edges of the slit, and so reaches the 

 third stomach. Here it undergoes further preparation, 



Stomach of a Ruminant. 



