446 ZOOLOGY. 
two small spurs, the vestiges of lateral toes. The two bones of the meta- 
tarsus and metacarpus are united into one called the cannon, but in certain 
species there are also vestiges of lateral metatarsal and metacarpal bones. 
The incisers are totally absent in the upper jaw, being only found in the 
lower one, and almost always eight in number. A callous pad is substituted 
for them above. Between the incisors and molars is a vacant space, where, 
in some genera only, are found one or two canines. The molars, almost 
always six throughout, have their crowns marked with two double crescents, 
the convexity of which is turned inwards in the upper and outwards in the 
lower ones. | 
Of all mammals, the ruminants are the most useful to man. They 
furnish him with food ; some serve him as beasts of burden; others with 
their milk, their leather, horns, tallow, &c. The tallow is produced by the 
fat, which in cooling down becomes brittle, a peculiarity that the fat of no 
other animal possesses. 
_ The group of Ruminantia divides naturally into four families, the camels, 
giraffes, deer and antelopes, and oxen. 
Fam. 1. Cametip#. The few members composing this family deviate 
a little from the ordinary ruminants, and show some slight affinity to the 
pachyderms. The number of molar teeth is smaller than usual; the first 
of these teeth is separated from the others by a large free space, and 
placed near the canine, which it resembles by its form, but generally falls 
off at an early age. In advance of the canine and in the upper jaw are 
found on each side an incisor, also resembling in its form that of the true 
canine, giving to the jaw the appearance of possessing three canines. In 
the lower jaw, the height of which reminds us of that of the horse, are only 
six incisors. Horns or other frontal processes are always wanting, as well 
as posterior claws or rudimentary toes. The hoofs are very small, situated 
near the extremity of the toe, and unable to support the body of the animal, 
which rests much more on a callous sole behind it. Of the two living 
genera composing this family, one is peculiar to the old, the other to the 
new world, both inhabiting the warm zone. The remains of an extinct 
genus have been found in Siberia. 
The genus Camelus is characterized by the presence of canines in both 
jaws, and six molars above and five below on each side. The jaws them- 
selves are slender, elongated, the nasal bones small; the posterior part of 
the skull is provided with very prominent crests and ridges; the temporal 
grooves are very deep. The lip is turned and cleft, the orbits prominent, 
the neck very long, the legs and feet disproportioned, giving to the camels 
a somewhat deformed appearance. The ease with which they are fed, 
and the faculty they possess of passing several days without drinking, 
make them of the highest importance for crossing the deserts. The inner 
wall of the paunch or first stomach is covered with large masses of cells, 
which retain for some time a certain quantity of water. Nothing of the 
kind is seen in other ruminants, although some pachyderms possess a 
similar provision. The camels have two toes united below nearly to the 
extremity by a common sole, and their back is furnished with lumps of fat. 
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