THE MAMMALS 237 
thirty to over a hundred feet in length with a weight of 
many tons. 
222. Hoofed mammals (Ungulata).—The order of hoofed 
animals or ungulates includes a large number of forms like 
the zebra, elephant, hippopotamus, giraffe, deer, and several 
other wild species, some of which are domesticated, such 
as horses, sheep, goats, and cattle. All of these animals 
walk on the tips of their toes, and the claws have become 
developed into hoofs. The order is divided into the odd- 
toed forms (perissodactyls), such as the rhinoceros with 
three toes and the horse with one, and the even-toed (artio- 
dactyls), as the pigs with four, and the ox, deer, etc., with 
two toes. The even-toed forms are again divided into 
those which chew the cud (ruminants) and those which do 
not (non-ruminants). No living native odd-toed mammal 
exists in this country, and of the wild even-toed species all 
are ruminants. In the members of this latter group the 
swallowed food passes into a capacious sac (the paunch), is 
thoroughly moistened, and passed into the second division 
(the honeycomb), later to be regurgitated and ground by 
the powerful molars. It is then reswallowed, and under- 
goes successive treatment in the other two divisions of 
the stomach (the manyplies and reed) before entering the 
intestine. 
Among the North American ruminants, the deer fam- 
ily (Cervide) is the best represented. In the more unsettled 
regions of the East the red deer is still common, and the 
same may be said of the white-tailed, black-tailed, and 
mule-deer of the West. Among the woods and lakes to 
the northward live the reindeer and caribou, and the largest 
of the deer family, the moose, which attains the size of the 
horse. Of nearly the same size is the wapiti or elk, whose 
general characters are shown in Fig. 134. In all of the 
above-mentioned species the horns, if present, are confined 
to the male (except in the reindeer), and are annually shed 
after the breeding season. 
