326 VERTEBRATE ANIMALS. 
The stomach in the Ruminants is complex, and is divided 
into several compartments, this being in accordance with their 
mode of eating. They all, namely, “ruminate” or ‘chew the 
cud ;” that is to say, they first swallow their food unmasticated, 
and then bring it up again after a longer or shorter period in ~ 
order to chewit. This is effected as follows (fig. 176) :—The 
vullet opens at a point between the first two compartments or 
stomachs, of which the largest lies to the left and is called the 
*‘ paunch,” whilst the smaller right cavity is called the “ honey- 
comb bag” (reticulum). The paunch (rumez) is the cavity into 
which the food is first received, and here it is moistened and 
allowed to soak for some time. After the food has lain suff- 
ciently long in the paunch, it passes into the “ honeycomb bag,” 
where it is made up into little balls or pellets, which are then 
Fig. 176.—Stomach of a Sheep. o Gullet; » Rumen or Paunch; 4 Honeycomb 
bag or Reticulum; ~ Many-plies or Psalterium; a Abomasum or Fourth 
Stomach, 
returned to the mouth by a reversed action of the muscles of 
the gullet. After having been thoroughly chewed, and prepared 
for digestion, the food is now swallowed a second time. On 
this occasion, however, instead of passing into the paunch, the 
masticated food is conveyed into the third stomach. This is 
known as the “many-plies” or “ Jsalterium,”’ because its lining 
membrane is thrown into a number of longitudinal folds, like 
the leaves of a book. The psalterium opens by a wide aperture 
into the fourth and last stomach, known as the “ abomasum.” 
This is a cavity of considerable size, which secretes the true 
digestive fluid (gastric juice), aud it is here that the food is 
y 
