B. 
THE FACIAL MUSCLES 
OF 
THE ELEPHANT. 
1. SPHINCTER-PLATYSMA-CROUP. 
pi. i. 
In the material at our disposal, of this group of muscles 
only the platysma and the auricular portion of the sphincter pro¬ 
fundus are present. Postponing the description of the latter muscle 
to the auricular muscles, we shall in this place only treat of the 
platysma. 
From the median dorsal line of the occiput and the neck 
there arises an aponeurosis; at its origin, thick, strong and con¬ 
taining some elastic tissue. It extends down the side of the neck 
where it gradually grows thinner and more fibrous, covers the 
surface of the parolis and then turns on to the face, on the out¬ 
side of m. masseter (in PI. 1 somewhat of the aponeurosis has 
been removed). 
The fleshy part of platysma arises from this aponeurosis; it 
extends upon the face and is divided into two rather well mar¬ 
ked portions, a mandibular portion and an angular portion. 
The mandibular portion arises nearly in the middle of the 
lateral face of the neck and forms a narrow ribbon-shaped muscle 
*) In dissecting the facial muscles of the Elephant we have made some observations 
relating to the skin and the hairs of the head, which may be recorded here. 
The corium is of very different thickness on different parts of the head. It is 
thickest postero-dorsally, between the ears; in the median line the corium is here 
2 cm thick and very dense. Forward it gradually diminishes in thickness, but 
still, in the median line between the eyes, the corium is 1 cm thick. The same 
thickness is preserved as far as the base of the trunk, but then rapidly diminishes 
distad over the trunk, so that the skin is soon only a couple of mm thick, and 
towards the tip of the trunk it is scarcely one mm thick. Laterally and vcntrally 
on the head the thickness of the skin is, on the whole, somewhat less than dor- 
sally; in some places, for instance round the eye, the skin is much thinner than 
in the surrounding parts. In most places the corium appears as a stratum, which 
may be dissected off, and such is also the case on the trunk unto very near the 
distal end; only in a few places, viz. in the tip of the trunk, in the inferior lip 
and in the upper lip (from the angle of the mouth to a point a little in front of 
the incisor) the corium forms a continuum with the underlaying muscular fascicles 
and connective tissue. 
As to the outer surface of the skin it is everywhere covered with small warts. 
On those parts, where the skin is thick, these warts are each furnished with a 
thick horny layer (resembling a short obtuse spine), and groups of these warts 
are here united into larger warts of different sizes, separated from the neighbouring 
prominences by deep furrows. 
The skin is furnished all over with hairs, which vary greatly in abundance. The 
hairs for the most part project nearly at right angles to the surface. They are 
mostly rather thick and rigid; their thickness is very variable. On the dorsal part 
which turns on lo the lower part of the face, covering the lower 
part of m. masseter; its upper margin is continued in the part 
of the aponeurosis which covers the rest of the masseter (omitted 
in PI. 1). On the left side of the head the muscle is inserted out¬ 
side the lower jaw, in front of the masseter. On the right side 
it divides into 3 branches, of which the inferior (PI. 1, a), rather 
a broad one, is inserted outside the lower jaw, in front of mas- 
seter; the second (PL 1, b), somewhat narrower branch turns 
a little upwards, thrusts itself under the lower part of m. bucci- 
natorius, and is inserted into the lower jaw just below this 
muscle; the uppermost branch (PI. 1, c) bends very much upwards 
and forwards and joins the angular portion. 
The angular portion arises from the aponeurosis on the out¬ 
side of the masseter. Behind the origin of the angular portion, 
and above the mandibular portion, a rather considerable part 
of the masseter thus remains free, covered only by the aponeu¬ 
rosis. On the left side the angular portion forms a closely con¬ 
nected muscle, which arises with 4 or 5 flat, broad portions; they 
join a little behind the angle of the mouth, the bundles running 
under each other and projecting into the m. buccinatorius. The 
of the head they are thickest, on the under side of the trunk remarkably fine. 
They may be rather long (5—7 cm), especially on the upper side of the head, 
round the opening of the ear and on the upper and lower lip, but most of the 
hairs are short stubbles. 
The hairs are found more closely arranged dorsally from behind lo the root 
of the trunk, but of a continuous hairy coat there is also here no question, there 
being rather considerable distances (2—5 mm) between the individual hairs. On 
the lateral aspect of the head (the cheek) they are more scattered, but become 
more numerous along lire margin of the lower jaw, and forward on the lower lip. 
On the eyelids, especially the upper eyelid, there are some few hairs. Along the 
margin of the upper eyelid the eyelashes are developed, which are numerous, long, 
and stiff: and arranged in several series; along the lower eyelid they are shorter 
and much less numerous. On the external ear Uiere are hairs scattered along the 
whole margin and single hairs on both surfaces; on the mediad surface they are 
very fine. Round the entrance into the meatus the hairs are more dense. 
Along the margin of the upper lip there are rather numerous hairs, of which 
some look almost as though they were vibrissae; but they have no sinus round 
them. On the lower lip there are some scattered long, thick and stiff hairs, which 
are real sinus-hairs. Along the whole length of the trunk there are short, thin, 
scattered hairs, most numerous on the dorsal and lateral sides. From about the 
middle of the trunk to the distal end there appear between these, especially la¬ 
terally, some long and stiff hairs, which are surrounded with a well-developed 
sinus. The digitiform prominence at the tip of the trunk is almost hairless, but 
the ventral margin of the nasal opening is studded with scattered quite short stiff 
hairs, round which we have found a small sinus. 
•i 
