E LEPH ANTID.E MAM il ALI A. E LEPIT ANTID/13. 
Family I.— ELEPHANTIDiE. 
Excluding the oceanic cetacea, tlie living represen- 
tatives of this family are the most bulky of all existing 
Mammalia. In the miocene and pleistocene deposits 
of the tertiary epoch, the remains of extinct species are 
extremely abundant ; some of them — such as the mas- 
todon, Plate 32, fig. 100, and deinotherium — being 
generically distinct. Probably the latter genus should 
be regarded as the type of a separate family, seeing 
that the lower jaw is supplied with enormous tusks, in a 
manner altogether unique ; their croYuis being directed 
downwards and backwards, and the roots inserted 
into a prolongation of the symphysis or anterior 
central prominence of the inferior maxillary bone. 
Whatever differences may have existed in these aber- 
rant forms, the true elephants are distinguished by the 
possession of a remarkable nasal appendage or proboscis, 
commonly called the “ trunk.” This organ has a taper- 
ing cornucopial outline ; it is pierced at the tip for the 
two nostrils, and at the centre of the upper margin is 
furnished with a finger-like process which, in con- 
junction with a thumb-like thickening of the inferior 
border, serves the purpose of a hand. The extra- 
ordinary prehensile powers of the trunk are familiar 
to every one ; but when it is considered how readily 
the same instrument can detach a straw or uproot a 
tree, our conceptions of its muscular and tactile powers 
can scarcely be too highly exalted. x\nother pecu- 
liarity in the organization of these proboscidean pachj'- 
derms has reference to the bidky aspect of the head. 
This feature, however, is not due to any increased 
development of the brain, but simply to a remarkable 
extension of certain air sinuses in connection with the 
cranial bones (fig. 69). The vertical elevation of the 
forehead thus confeired upon the elephant, has led 
many to ascribe to the animal an almost super-quad- 
rupedal intelligence ; but if, in this case, their opinions 
are based upon phrenological considerations, it is 
our duty to inform such enthusiasts that the frontal 
prominence and elevation of the cranial vertex bear no 
relation whatever to the bulk of the brain contained 
within the comparatively restricted cerebral cavity. 
That elephants jiossess considerable sagacity, no one 
will venture to deny; but that they display this mental 
quality in virtue of any corresponding enlargement 
of the great nervous centre, is utterly inadmissible. 
Another interesting peculiarity in this family consists 
in the form and arrangement of the teeth. Ordinarily, 
it is stated that the dentition comprises two incisors, 
no canines, and three molars ; but in reality the grinders 
are more numerous, no less than seven being conse- 
cutively developed on each side of either jaw. This 
apparent discrepancy results from the circumstance, 
that only two molars are present on one side of either 
jaw at the same time ; but, in the progress of growth 
and age, those first employed give way to a succession 
of similar teeth developed from behind. In like manner 
the two large permanent incisors are preceded by a 
similar pair, which, however, have never attained full 
development. Histologically speaking, the tusks con- 
sist entirely of dentine, which, on transverse section. 
181 
exhibits an elegant series of decussating curvilinear 
strise. This appearance is peculiar to the ivory of 
elephants, and considerably enhances its commercial 
value. In a structural point of Hew, the molars are 
Fig. 69. 
Vertical Section of the Skull of the Elephant. 
still more remarkable. If reference be made to Plate 
32, fig. 102, it will be observed that the grinding surface 
is marked by a number of parallel bars. These consist 
of alternating plates of the three different substances 
which ordinarily enter into the composition of the 
mammalian tooth ; the white bands representing plates 
of enamel, each inclosing a central lamina of ivory or 
dentine, whilst the several outer spaces between these 
formations are filled up with a special osseous devel- 
opment termed cement. In the African elephant the 
enamelled plates have a lozenge-shaped outline, as 
seen in Plate 32, fig. 101 ; in the Siberian mammoth, 
or Elephas primigenius, they are more numerous and 
closely approximated ; and in the mastodon are elevated 
into a series of tuberculatcd cones. In regard to the 
skeleton, we may remark the general massiveness of all 
the bony elements, the twenty pairs of ribs reaching 
backwards almost to the pelvds, the remarkable breadth 
of the scapula in proportion to its length, the prodigious 
development of the external condyle of the humerus, 
the simple form of the femur, the peculiar articulation 
of the superior extremity of the radius, and the odd- 
toed, peiitadactylous feet. The digestive organs are 
extremely bulky as in herbivorous quadrupeds gene- 
rally. The gall-bladder is complicated by numerous 
internal septa, and intimately connected with the walls 
