fibrous substances, and the digestion of the cellulose. Between sixty and
seventy per cent of the cellulose is digested in the rumen.

_The abomasum_ is lined by a gastric mucous membrane. The gastric juice
secreted converts the protein into peptones. In the young a milk curdling
ferment is also secreted by the glands of this compartment.

THE STOMACH OF THE HOG is a type between the carnivora and ruminant. The
digestive changes may be divided into four stages. The first period is one
of starch conversion; the second period is the same, only more pronounced;
the third period, both starch and protein conversion occurs; and the fourth
period is taken up mostly with protein digestion.

ACUTE INDIGESTION OF THE STOMACH OF SOLIPEDS.--Diseases of the stomach are
less common in solipeds than in ruminants. The simple stomach of the horse
and the comparatively unimportant place that it occupies in the digestion
of the feed renders it less subject to disease. Only under the most
unfavorable conditions for digestion of the feed does this class of
disorders occur. Acute indigestion in the form of overloading and
fermentation occurs in the stomach (Fig. 11).

_The predisposing causes_ that have to do with the development of these
disorders, are the small capacity of the stomach and the location and
smallness of the openings leading from the oesophagus and into the small
intestines. Greedy eaters are more prone to indigestion than animals that
eat slowly and are fed intelligently.

[Illustration: FIG. 11.--Dilated stomach of horse.]

_The following exciting causes_ may be mentioned: Sudden changes in ration;