=Omnivora= occupy a place intermediate between these two classes, as regards both the nature of the food and the extent of surface of the alimentary canal, and they are in similar ratio little liable to digestive disorders. They have besides in common with carnivora a great facility in the rejection of irritant matters by vomiting, and in thus protecting themselves against gastric and intestinal disorders. A fair idea of the area of the intestinal surface may be given by stating the length of the canal relatively to that of the body:—in the dog : : 6 : 1, in the rabbit : : 10 : 1, in the ass and mule : : 11 : 1, in the horse : : 12 : 1, in swine : : 14 : 1, in the ox :: 20 : 1, and in the sheep : : 27 : 1. The calibre of the intestine varies however and with it the capacity. Thus in the relatively shorter intestine of the horse, the capacity is much greater in ratio with the size of the animal than is the relatively much longer intestine of the pig. The ox’s intestine though twice the length of that of the horse has little more than half the capacity. Among =herbivora= the monogastric (horse, ass, mule), and polygastric (ruminants) animals manifest varying pathological susceptibility according to the relative development of the different digestive viscera and the habitual character of their food. The horse and other large solipeds have small stomachs (16 qts.) and capacious intestines (196 qts.). Digestion is restricted in the stomach and largely carried on in the spacious bowels. The small stomach requires to be frequently replenished in moderate amount, but, if this is secured, its liability to disease is slight while that of the intestines is very considerable. In the ox the stomachs have a total capacity of 252 qts., while that of the intestines averages 103 qts. In this animal the capacious and hard working stomach is a frequent seat of disorder, while the comparatively small intestines are to a large extent exempt. The small stomach of the horse is easily overloaded and disordered or paralyzed by an unusually full feed of grain when hungry, or one of some specially appetizing fodder, and the case is serious, as relief can rarely be obtained by vomiting. For the same reason fermentation of the gastric contents with evolution of gas and tympany usually proves fatal to the horse since relief by eructation is too often impossible. Cattle are fitted to live in damp localities where the cloven foot prevents sinking and getting bogged, and where they may draw in with the tongue a full mouthful of coarse herbage which they swallow with little mastication or admixture with saliva. This lodges in the first two stomachs, and if, from any cause, rumination is impaired, or suspended, it finds itself in conditions especially favorable to fermentation. The food too, as in the case of frosted roots, wet clover or partially ripened grain, etc., is often charged with ferments (bacteria) in a state of great vital