PLANT-EATING MAMMALS 169 



semblance to a honey-comb; this compartment opens into the 

 (3) manyplies (psalter or omasum), the name of which suggests 

 the fact that its lining is raised into numerous folds, projecting 

 almost like the leaves of a book (such as a psalter or psalm-book, 

 for instance) into its cavity; the manyplies is continued into the 

 last compartment, (4) the rennet stomach (reed, abomasum), from 

 which the small intestine leads out. The first three chambers are 

 lined by a thick hard membrane, reminding us of the left-hand 

 part of the horse's stomach, and it is not unlikely that in both 

 cases we have to do with a dilated part of the gullet, comparable 

 to the crop of a bird, and not really a part of the stomach at all. 

 The fourth or last compartment is the true chemical stomach, and 

 is lined by a soft membrane secreting the gastric juice. This con- 

 tains pepsin, and also a milk-curdling substance (rennin), which is 

 the source of the rennet used in cheese-making. 



The food is cropped rapidly, and swallowed without being 

 properly chewed, passing into the paunch. Here it gets into a 

 sodden condition, and later on, when the animal begins to " chew 

 the cud ", is made up into boluses in the honey-comb stomach, and 

 returned to the mouth for thorough mastication. While this is 

 being effected the lower jaw is moved from side to side from 

 left to right, and right to left alternately the articulation of the jaw 

 being so constructed as to permit of this (see vol. i, p. 29). After 

 the second and thorough chewing the food is conducted along a 

 groove into the manyplies, which acts as a strainer, and thence 

 into the rennet stomach, where gastric juice is poured upon it. 

 The conditions of life under which the primitive ruminants existed 

 account for the evolution of the complex stomach. The grass 

 constituting their food would be most abundant on the plains, and 

 here they would be exposed to the attacks of Carnivores. The 

 power of rumination enables its possessor to rapidly obtain and 

 swallow a large bulk of herbage, retiring afterwards to a place 

 of safety, where the process of mastication can be completed at 

 leisure. 



It is a commonplace that ordinary ruminants, just like Lions 

 and Tigers among the Carnivora, find their food on or near the 

 ground; though some of them, Goats, for instance, rear up on 

 their hind-legs so as to browse on leaves and shoots otherwise 

 out of reach. It has, however, recently been shown that a 

 common South African antelope, the Blue-Buck (Cephalophus 



