nwt eee 
PACHYDERMATA. 875 
maxillary bone in front of the zygomatic pro- 
cess: these muscles are partially united, but 
their tendons run separately to be inserted, one 
into the side, the other into the base of the 
snout. The fourth pair is comparatively of 
small size, arising from the nasal bone, and 
running obliquely beneath the tendons of the 
two last, terminates near their insertion. The 
snout and all the above longitudinal muscles 
are moreover enclosed by a layer of annular 
fibres, which are a continuation of the orbicularis 
oris, so that considerable mobility in any 
required direction is thus amply provided for. 
n the construction of the snout of the Tapir 
the arrangement of the nasal cartilages and 
muscles of the nose is still more elaborate, 
forming a rudimentary proboscis which is only 
surpassed in complexity by the trunk of the 
Elephant, the only existing type of the true 
Proboscidian Mammalia: in fact it is con- 
structed upon the same principles, the great 
difference consisting in the diminutive size of 
the organ in the Tapir when contrasted with 
the prodigious dimensions of the corresponding 
parts in the Elephant’s proboscis. The nose of 
the Tapir iscomposed of two membranous tubes, 
amply provided with mucous lacune, and en- 
closed in a fleshy mass surrounded by the skin, 
which consists of longitudinal muscles that take 
their origin beneath the lower margin of the orbit, 
and of fasciculi of transverse fibres passing be- 
tween the skin and the external surface of the 
membranous nasal tubes. There is a pair of 
muscles in every way similar to the elevators of 
the upper lip of the Horse, derived from the pre- 
cincts of the orbit, and uniting into a common 
tendon to be inserted into the upper aspect of 
the nose, a pair of depressors arising from the 
intermaxillary bones, and also a slip derived 
from the occipito-frontalis, which is implanted 
by the intervention of a tendon into the base of 
the proboscis. 
The proboscis of the Elephant, the only 
existing example of a completely developed 
nasal apparatus, forms an elongated cone of 
four or five feet in length, and gradually taper- 
ing from the root towards the point, which is 
terminated by a kind of thumb-like appendage 
which is endowed with exquisite sensibility, so 
as to be useful in picking up the smallest 
objects. Internally the Elephant’s trunk is 
perforated by a double tube, formed by a 
strong tendinous membrane, through which in- 
numerable mucous crypts pour fluid abundantly 
into the nose. The membranous tubes are 
continved upwards as far as the bony nostrils, 
but, a little before their junction with the latter, 
they form two curves, the nasal passages being 
closed at this point by a cartilaginous elastic 
valve, which may be opened at the will of the 
animal, but closes by its own elasticity when 
the muscles which open it cease to act. 
All the interval between the membranous 
tubes which follow the axis of the proboscis, 
and the skin by which it is invested externally, 
is filled up with a thick layer of muscular 
substance composed of two sets of fibres. Of 
these one set passes from the exterior of the 
membranous tubes to a strong tendinous mem- 
brane situated immediately beneath the skin in 
such a way that on making a transverse section 
of the trunk, these muscles represent the radii 
of acircle: their actiow will be, of course, to 
approximate the membranous tubes and the 
external integument of the trunk, and thus, by 
compressing the intervening space, their con- 
traction will have the effect of elongating the 
whole proboscis, without at the same time . 
diminishing the calibre of the membranous 
tubes, as would have been the case had annular 
fibres been employed instead of this remarkable 
arrangement. 
The other muscles of the proboscisare disposed 
longitudinally, and form a multitude of fasci- 
.culi, disposed in short curves in such a manner 
that the two extremities of each fasciculus are 
implanted into the membranous tubes, while 
the convexity of the arch is adherent to the 
external tendinous membrane. These fasciculi 
surround the whole trunk, and extend along 
its entire length; their effect being to shorten 
it from end to end or in any part the animal 
may please. It is evident that by these partial 
elongations or shortenings of one side or the 
other, the Elephant can bend its trunk in any 
direction. with the utmost ease, and make use 
of it as efficiently as a hand in the performance 
of many important offices. In addition to the 
above account of the anatomy of this remark- 
able apparatus given by the Parisian Acade- 
micians, Cuvier ascertained that all the longitu- 
dinal fasciculi which enter into the composition 
of the trunk are derivations from four great 
muscles, which, though almost blended together 
in the trunk itself, are distinct enough near 
their commencements. Of these the two ante- 
rior arise from the whole breadth of the frontal 
bone above the ossa nasi, while the two lateral 
muscles take their origins from the superior 
maxillary bones beneath and in front of the 
orbit. The posterior or inferior aspect of the 
Elephant’s proboscis is covered with fibres, 
which seem to be continuations of the orbicu- 
laris oris, and which run obliquely downwards 
and inwards so as to meet their fellows from 
the opposite side at an acute angle. With 
such a structure it is evident that the nasal 
prolongation of the Proboscidian Pachyderms 
is able to move in every needful direction, and 
perform all the duties of a lithe and flexible arm, 
strong enough to tear the branches from the 
trees, and sufficiently manageable to be avail- 
able for the most delicate manipulations. 
The instruments of the senses present few 
peculiarities. 
In connection with the organs of smell we 
may conveniently mention the sinuses which 
communicate with the nasal cavities, which in 
many Pachydermata are extremely developed. 
The frontal sinuses of the Elephant are of 
enormous extent, reaching throughout all the 
thickness of the frontal, of the parietal, of the 
temporal, and even extending into the condyles 
of the occiput. The whole of this extensive 
cavity is divided into cells by numerous imper- 
fect septa, irregularly disposed. In the Hog 
tribes they are equally extensive, but far more 
shallow; they reach as far back as the occiput, 
