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Elephant.

Muscular system of the trunk. Ear-muscles.

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Furthermore in the proboscis the whole system of the radial
fascicles, the m. rectus nasi, is found, and they are certainly of
great importance in many respects. It can hardly be doubted
that, by their contraction, they will dilate the nasal tubes, so
that they can support the m. lateralis nasi in its action (v. p. 39),
when the animal sucks up water in the trunk. Further it is
surely this muscular system which produces the elongation1) of
the trunk; the Elephant can stretch the trunk. When the rectus
system contracts, the skin and the walls of the nasal tubes approach
, and when at the same time the other muscles are relaxed
, the trunk will by this means be elongated. Finally, there
can be no doubt but that the rectus system is of great importance
in so far as the activity of the m. maxillo-labialis is concerned
. And this because contraction of the rectus-fascicles will
fix the aponeuroses, from which, as we have already pointed out,
the longitudinal fascicles take their origin and into which they
are inserted.

Finally we add the following comments: The entrance to
the nasal tubes, at the point of the trunk, is, as is well-known,
in the Indian Elephant limited dorsad by an elongation shaped
like a finger, ventrad by a lip-shaped fold of the skin. »The fin-
ger« and »the lip« can be separated, or brought together. In the
former motion »the finger« is raised by contraction of the fascicles
of the portio superior m. maxillo-labialis, while »the lip«
is drawn down by the fascicles of the pars rimana, which, just
on the distal part of the trunk, take a direction that nearly approaches
the longitudinal. The opposite motion, the bringing together
of »the finger« and »the lip«, by which the animal can
seize objects, is, on the contrary, executed by the portio supra-
labialis, whose fascicles, on the distal end of the trunk, run so
obliquely that they almost approach the transverse direction.

In the cheek of the Elephant we have found a system of
fascicles which from the mucous membrane radiate transversally,
a »/7?. rectus buccce«, analogous to the m. rectus nasi. From the
mucous membrane, partly from both faces of the great fold mentioned
(v. p. 35), partly, in front of and behind it, there arises
a rather considerable mass of thick fascicles that radiate transversally
, some of them in a low bow, thrusting themselves in
between the longitudinal fascicles of the m. buccinatorius, where
they end. Particularly behind the great fold of the mucous membrane
these fascicles appear in considerable numbers. In none
of the other Mammals examined we have found anything corresponding
.

In the upper lip with the exception of the proboscis we have
found no rectus-bundles. In the under lip there are numerous rectus-
bundles going from the inner side of the spout-formed anterior part
of the under lip to the outer side of the same — the only muscular
elements in this part of the under lip. Posteriorly these
rectus-bundles close the numerous bundles of the m. mentalis,
as the anterior continuation of which muscle they appear.

7. MUSCLES OF THE EXTERNAL EAR.

PL 1; PL 15, fig. 7.

The external ear of the Elephant, with its muscles, is peculiar
in that, for the most part, it is situated on the neck, and
the muscles to a larger extent than usual take their origin from
the neck.

A scutellum is not present; but there is a tendinous stripe
in the muscular plate formed by a number of the greater ear.
muscles, which without doubt is the representative of the lost
scutellum.

a. Scutularis-group.

The m. scutularis is represented by the following portions.

Above, and close behind, the eye there arises from the skull
a short flat muscular belly, No. 1, whose fibres are directed upward
and hindward; it is continued by a long narrow, and strong
tendon, which slightly arcuate runs above the great facial gland.

*) Comp. Harrison, Anatomical Observations of some parts of the Elephant.
From Proc. R. Irish Acad. Vol. 3 (1847). p. 12.

A little above this muscular belly lies a rudimentary muscle,
No. 2, which also is continued into a tendon, which soon joins
that of No. 1. The joint tendon passes behind the facial gland
into a powerful muscle, No. 3, whose fibres have a horizontal
direction, and which are inserted, fleshy, into the convex side of
the auricle near the anterior margin below the anteron 7. With
No. 3 is again another considerable muscle connected, No. 4, which
arises from the connective tissue outside the m. temporalis, and
from the skull behind the temporal fossa. The fibres thereof are
directed backward and a little downward; inferiorly it passes
without any limit into No. 3. The upper part of No. 4 is inserted
into a tendinous stripe, the homologue of the scutellum, into which
also the m. auriculo-occipitalis is inserted.

The muscles 1, 2, 3 and 4 together represent the m. scutularis
; No. 3 is the pars transiens. The portions designed as No. 1
and 2 are similar to the detached foremost part of the scutularis
in the Tapir (PI. 7).

M. rotator. From the tendinous stripe mentioned above, and
from a line on the inside of the scutularis lying in the continuation
of this stripe a short strong muscle, No. 5, arises which is inserted
into the convex surface of the auricle near the anterior margin
(at the base of the anteron 5), above the insertion of the deep
portion of the postauricularis. The direction of the fibres are
principally dorso-ventrad.

Although the direction of the fibres of the m. rotator is generally
more before-backward and the insertion also somewhat
more backward, the muscle described cannot be anything but
the rotator. The altered direction of its fibres is dependent on
the alteration of the place of the whole ear; and the difference
in the insertion is insignificant.

b. Auriculo-occipitalis-group.

The /7?. auriculo-occipitalis is split up into two quite distinct
portions, which both arise near one another from the fascia covering
the large muscles of the neck; they arise rather far from
the skull, and from the middle line. The anterior (or superior)
portion (No. 6), which may again be separated into two halves,
lying close to one another, corresponds to that part of the auriculo
-occipitalis which in other Mammals is inserted into the scutellum
. It is inserted into the tendinous stripe, described above
as the homologue of the scutellum. At the insertion, its fascicles
cross those of the upper portion of the scutularis. Some of the
inferior bundles thereof join the external side of the rotator. —
The posterior (inferior) portion (No. 7) is a long rather strong, but
narrow muscle which arises from the same fascia close below
the anterior portion. It is inserted into the mediad side of the
auricle near the anterior margin close below the insertion of the
pars transiens musculi scutularis. It has a broad plane of insertion
, while usually the auricular part of the auriculo-occipitalis
is inserted into a long transverse line.

The Elephant is not the only Mammal, in which the auricular
portion of the auriculo-occipitalis has been quite separated
from the rest of the muscle. In the Elk, for instance, the same
is the case.

The m. postauricularis is represented by three quite separated
muscles, of which two represent the superficial, the third the deep
portion. Of the two muscles representing the superficial portion
the superior (No. 8) arises on the side of the neck covered by the
auricular portion of the auriculo-occipitalis and is inserted into
the mediad side of the auricle, close below the insertion of the
same auricular portion. The inferior (No. 9) arises close below the
auricular portion of the auriculo-occipitalis, to which both muscles
(No. 8 and 9) are similar in form, and is inserted at a rather
great distance from No. 8 close above the hind end of No. 12. —
The deep portion (No. 10) is a broad rather strong muscle lying
on the m. splenius, surrounded by a fibrous sheeth and adipous
tissue; it is inserted into the auricle below the insertion of the
rotator near the anteron 5.

The m. adductor inferior (No. 11) is a peculiar little short and
broad muscle lying in front of the ear-opening. The muscle,
which is somewhat fanshaped, arises for the greater part from