there is too much reason to believe that the pursuit will ultimately end in the destruction of these fine animals. A great deal, however, of the ivory of commerce comes from Siberia, and is really derived from the tusks of the now extinct Mammoth, which formerly inhabited the north of Asia in great numbers.

The Elephants are all phytophagous, living entirely on the foliage of shrubs and trees, and other vegetable matters, which they strip off by means of the prehensile trunk. As the tusks prevent the animal from drinking in the ordinary manner, the water is sucked up by the trunk, which is then inserted into the mouth, into which it empties its contents.

Closely allied to the true Elephants are the Mastodons, characterised by the fact that the crowns of the molar teeth have nipple-shaped tubercles placed in pairs (fig. 373). Gen

A

B

Fig. 373.-A, Skull of Mastodon giganteum; B, Side-view of the second true molar of Mastodon giganteum. (After Owen.)

erally speaking, the two upper incisors formed long curved tusks, as in the Elephants, but in some cases there were two lower incisors as well. The various species of Mastodon all belong to the later Tertiary and Post-tertiary periods.

The last of the Proboscidea is a remarkable extinct animal, the Deinotherium. This extraordinary animal has hitherto only been found in Miocene deposits, and little is known of it except its enormous skull. Molars and præmolars were present in each jaw, and the upper jaw was destitute of canines and incisors. In the lower jaw were two very large tusklike incisors, which were not directed forwards as in the true Elephants, but were bent abruptly downwards (fig. 374). The animal must have attained an enormous size, and it is probable that the curved tusks were used either in digging up roots, or

in mooring the animal to the banks of rivers, for it was probably aquatic or semi-aquatic in its habits. It is placed by

Fig. 374.-Skull of Deinotherium giganteum.

De Blainville in the Sirenia, being regarded as a Dugong with tusk-like lower incisors; but this view has been rendered untenable by the discovery of limbbones of a distinctly Proboscidean type.

As regards the distribution of the Proboscidea in time, the order came into existence in the Miocene period, where it is represented by all its three sections, Deinotherium, Mastodon, and Elephas.

The genus Deinotherium, as just mentioned, is exclusively

confined to the Miocene period.

The genus Mastodon is characteristic in Europe of the Miocene and Pliocene; but in North America it is represented in the Post-Pliocene, and it occurs also in deposits of the same age in South America.

No Elephant has yet been discovered in the Miocene rocks of Europe, but six species are known from Miocene strata in India. In the Pliocene period Europe possessed its Elephants (viz., E. priscus and E. meridionalis); but the best known of the extinct Elephants, as well as the most modern, is the Mammoth (E. primigenius, fig. 375).

Fig. 375.-Skeleton of the Mammoth (Elephas primigenius).

This enormous animal is now wholly extinct, but it formerly abounded in the northern parts of Asia and over the whole

of Europe. It occurred also in Britain, and unquestionably existed in the earlier portion of the human period, its remains having been found in a great number of instances in connection with human implements. From its great abundance in Siberia, it might have been safely inferred that the Mammoth was able to endure a much colder climate than either of the living elephants. This inference, however, has been rendered a certainty by the discovery of the body of more than one Mammoth embedded in the frozen soil of Siberia. These specimens had been so perfectly preserved that even microscopical sections of some of the tissues could be made; and in one case even the eyes were preserved. From these specimens we know that the body of the Mammoth was covered with long woolly hair.

CHAPTER LXXVI.

CARNIVORA.

ORDER XII. CARNIVORA.-The twelfth order of Mammals is that of the Carnivora, comprising the Fera, or Beasts of Prey, along with the old order of the Pinnipedia, or Seals and Walruses, these latter being now almost universally regarded as merely a group of the Carnivora modified to lead an aquatic life.

The Carnivora are distinguished by always possessing two sets of teeth, which are simply covered by enamel, and are always of three kinds-incisors, canines, and molars-differing from one

3-3

another in shape and size. The incisors are generally 3 3

I-I

(except in some seals); the canines are always and are

I-I'

invariably much larger and longer than the incisors. The præmolars and molars are mostly furnished with cutting or trenchant edges; but they graduate from a cutting to a tuberculate form, as the diet is strictly carnivorous, or becomes more or less miscellaneous. In the typical Carnivores (such as the Lion and Tiger), the last tooth but one in the upper jaw and the last tooth in the lower jaw are known as the "carnassial" teeth, having a sharp cutting edge adapted for dividing flesh, and generally a more or less developed tuberculated heel or process. A varying number, however, of the molars and præmolars may be "tubercu

late," their crowns being adapted for bruising rather than cutting. As a general rule, the shorter the jaw, and the fewer the præmolars and molars, the more carnivorous is the animal. The jaws are so articulated as to admit of vertical but not of horizontal movements; the zygomatic arches are greatly developed to give room for the powerful muscles of the jaws; and the orbits are not separated from the temporal fossa. The intestine is comparatively short.

In all the Carnivora the clavicles are either altogether wanting, or are quite rudimentary. The toes are provided with sharp curved claws. The teats are abdominal; and the placenta is deciduate and zonular.

The order Carnivora is divided into three very natural sections:

Section I. Pinnigrada or Pinnipedia.-This section comprises the Seals and Walruses, in which the fore and hind limbs are short, and are expanded into broad webbed swimming-paddles (fig. 376, B). The hind-feet are placed very far back, nearly

Fig. 376.-Feet of Carnivora (after Owen). A, Plantigrada, Foot of Bear;
B, Pinnigrada, Hind-feet of Seal; C, Digitigrada, Foot of Lion.

in a line with the axis of the body, and they are more or less tied down to the tail by the integuments.

Section II. Plantigrada.-This section comprises the Bears and their allies, in which the whole, or nearly the whole, of the foot is applied to the ground, so that the animal walks upon the soles of the feet (fig. 376, A).

Section III. Digitigrada.-This section comprises the Lions, Tigers, Cats, Dogs, &c., in which the heel of the foot is raised

entirely off the ground, and the animal walks upon the tips of the toes (fig. 376, C).

SECTION I. PINNIGRADA or PINNIPEDIA.-This section of the Carnivora comprises the amphibious Seals and Walruses, which differ from the typical Carnivores merely in points connected with their semi-aquatic mode of life. The body in these forms is elongated and somewhat fish-like in shape, covered with a short dense fur or harsh hairs, and terminated behind by a short conical tail. All the four limbs are present, but are very short, and the five toes of each foot are united together by the skin, so that the feet form powerful swimmingpaddles. The hind-feet are of large size, and are placed far back, their axis nearly coinciding with that of the body (figs. 376, 377). From this circumstance, and from the fact that the

integument often extends between the hind-legs and the sides of the short tail, the hinder end of the body forms an admirable swimming apparatus, similar in its action to the horizontal tail-fin of the Cetacea and Sirenia. The tips of the toes are furnished with strong claws, but the powers of terrestrial locomotion are very limited. On land, in fact, the typical Seals can only drag themselves along laboriously, chiefly by the contractions of the abdominal muscles. On the other hand, the Eared Seals (Otariada) can use their hind-limbs freely upon the land. The ears are of small size, and are mostly only indicated by small apertures, which the animal has the power of closing when under water. The bones are light and spongy, and beneath the skin is a layer of fat or blubber. The dentition varies, but teeth of three kinds are always present, in the young animal at any rate. The canines are always long and