Elepnantid.e JIAJIJIALIA. Ei.EPTiANTin.E. 



181 



Family I.— ELEPIIANTID^. 



Excluding the oceanic cetacea, tlie living represen- 

 tatives of tliis family are the most hulky of all existing 

 Mammalia. In the miocene and pleistocene deposits 

 of the tertiary epoch, tlie remauis of extinct species are 

 extremely abmidant ; 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 tlie type of a separate family, seeing 

 that the lower jaw is supplied with enormous tusks, in a 

 manner altogether unique ; their crowns being directed 

 downwards and backwards, and the roots inserted 

 into a prolongation of the symphysis or anterior 

 central prominence of the inferior maxillary bone. 

 AVhatever diilerences 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 " tmnk." 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 

 fui'uished with a flnger-like process which, ui con- 

 junction with a tlunub-like thickening of the inferior 

 border, serves the purpose of a hand. The extra- 

 ordinary prehensile powers ol the trunk are familiar 

 to every one ; but when it is considered how readily 

 the same mstrunient can detach a straw or uproot a 

 tree, our conceptions of its muscular and tactile powers 

 can scarcely be too highly exalted. Another pecu- 

 liarity in the organization of these proboscidean pachy- 

 derms has reference to the bulky aspect of tlie head. 

 This feature, however, is not due to any increased 

 development of tlie brain, but simply to a remarkable 

 extension of certain air sinuses in connection with the 

 cranial bones (fig. G9). The vertical elevation of the 

 forehead thus conferred upon the eleiihant, has led 

 many to ascribe to the animal an almost super-quad- 

 lupedal mtelligence ; 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 caA-ity. 

 That elephants possess 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 pecidiarity in this fomily 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 

 juw at the same time ; Init, in the progi-ess 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. Ilistologicallj' speaking, the tusks con- 

 sist euthely of dentme, which, on ti'ansverse section, 



exhibits an elegant series of decussating curvilinear 

 striie. This appearance is peculiar to tlie ivory ot 

 cle[)hants, and considerably enhances its commercial 

 value. In a structural point of view, the molars are 



^'4 



% ^S;.^^ 



Vti-tical Secticn uf ihi- SkiiU uf ilie Llf, h .m. 



still more remaikable. If reference be made to Plate 

 32, fig. 102, it will be observed that the grinding surAice 

 is marked by a number of parallel bars. These consist 

 iif alternating plates of the three diU'erent substances 

 which ordinarily enter into the composition of llie 

 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 elejihant the 

 enamelled plates have a lozenge-shaped outline, as 

 seen in Plate 32, fig. 101 ; in the Siberian mammoth, 

 or Elephas pririiifjeniiis, they are more numerous and 

 closely ajiproximated; and in the mastodon are elevated 

 into a series of tuberculated cones. In regai'd to the 

 skeleton, we may remark the general massiveness of all 

 the bony elements, the twenty pairs of ribs reaching 

 backwards almost to the pelvis, the remarkable breadth 

 of the scajiula m proportion to its length, the prodigious 

 development of the external condyle of the humerus, 

 the simple form of the femur, tlio peculiar articulation 

 of the superior extremity of the radius, and the odd- 

 toed, pentadactylous 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 w^tli the walls 



