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Elephant.

Orbicularis-oculi-group. Maxillo-labialis.

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whereas the anterior ones turn forwards in a bow. The fascicles
terminate in narrow pointed tendons, which are inserted into
the connective tissue above the angle of the mouth, into the
upper lip, and on to the base of the trunk. The posterior fascicles
are inserted slightly above the angle of the mouth about level
with the lower margin of the proc. z}^gomaticus of the maxilla,
partly level with the neighbouring ventral prseorbicularis-fascicles,
some of which, however, interlace between the nasolabialis-fas-
cicles. In front the fascicles gradually grow longer and run, in
a bow, into the upper-lip, partly crossing partly projecting between
the fascicles of m. nasalis.

Some of the anterior fascicles (in PI. 4 there are four such)
are rather peculiar: Each fascicle passes into a long thin tendon,
which runs forwards in a bow and passes into a new muscular
fascicle which quite closely joins the portio inferior m. maxillo
-labialis. In this way there is formed a succession of small
»musculi digastrici«, stretched between the m. nasolabialis and
the m. maxillo-labialis. To suppose that these fascicles are the
remains of an original connection between the m. nasolabialis
and the m. maxillo-labialis would be quite wrong. Indeed, our
investigations have shown that these two muscles are independent
, quite separate from each other. So there is nothing
left but to regard these fascicles as a mere secondary connection
between the said muscles. We must add however that in the Elk
and the Zebu we have also found a connection between the m.
nasolabialis and the m. maxillo-labialis, but developed in a way
other than that in the Elephant. In the Ungulates we have generally
found that the m. maxillo-labialis to a greater or smaller
degree pierces the m. nasolabialis and in this place, which in
the Elk and the Zebu is much in front of the face, some naso-
labialis-fascicles are inserted into the tendinous slips of maxillo-
labialis. (As to details v. the special descriptions in the Appendix
; also compare PL 11, fig. 1 where these nasolabialis-fascicles
are figured).

A little above the eye there is a small muscle, arising from
the connective tissue outside the frontal bone, and passing obliquely
backwards (PI. 1 and 4). The fascicles are quite short and
do not pass into the eyelid at all. The muscle is much more
narrow on the right side of the head than on the left. We feel
a doubt as to the explanation of this small muscle. Judging
from its position we are most inclined to regard it as a very
much reduced m. supraorbicularis; indeed, the direction of the
fascicles does not appear to be in favour of this, but we have
also in other places found such alterations of the course of the
fascicles (compare e. g. the portio palpebralis sphinct. prof, in
the Horse).

The orbicularis-group in the Elephant is composed of the
same components as in the Ungulates. There is a m. orbicularis,
post- and prseorbicularis, supraorbicularis and nasolabialis. The
orbicularis itself is peculiar in its complete want of circular fascicles
, which seem to be constantly present in the Ungulates, though
sometimes only in small numbers. In none of the Ungulates investigated
was there so powerful a m. postorbicularis as in the
Elephant, whereas the m. prseorbicularis of the latter is somewhat
reduced. This applies also to the m. supraorbicularis, which
is very much reduced in the Elephant. As to the m. nasolabialis
it is feebly developed in the Elephant, while it is generally well
developed in the Ungulates. It is especially notable, that it has
not contributed towards the formation of the muscular system
of the trunk, but has been limited to the upper lip proper. The
origin of the muscle is in the Elephant concentrated into a small
portion of the frontal bone, while in the Ungulates it has a more
considerable extension.

The account of the orbicularis-group in Miall and Greenwood
is very deficient; it evidently suggests a less careful investigation.—
Watson describes the orbicularis palpebrarum as consisting of
»two sets of fibres, an internal and an external«; the internal portion
is the proper »orbicularis« and is said to consist of circular
fascicles (only interrupted in front); the »external portion« evidently
corresponds to our m. prse- and postorbicularis. The m. nasolabialis
(levator labii superioris Watson) is said to consist of
an anterior and a posterior portion. This we have not found
at all.

3. MUSCULUS MAXILLO-LABIALIS.

PI. 1; 2; 4; 14, fig. 2.

This muscle in the Elephant has been developed to a very
high degree in consequence of its share in forming the trunk.
On the whole dorsal side and part of the lateral face of the latter
it forms a powerful, longitudinal muscular mass, arising from the
cranium with two distinctly separated portions, the portio superior
and the portio inferior.

The portio inferior is the smaller one (PI. 2); it arises, with
two or three short and narrow tendons, from (he projecting corner
of the maxillary bone just laterad of the foramen infraorbi-
tale. The tendons pass into a rather narrow muscle, which goes
straight forwards and very soon merges into the portio superior.
Together with the latter it passes out upon the lateral face of
the trunk and runs to its extreme distal end, where its outmost
fascicles are inserted into the lateral circumference of the nostril.
The origin is quite covered by the m. nasolabialis, whereas the
first part of the muscle is partly covered, partly traversed, by
the bundles of the m. nasalis. This traversing is most extensive
on the right side, an anterior, rather broad bundle here thrusting
up through the muscle and, as it were, separating it into a lateral
and a mediad portion, which, however, in front of the m.
nasalis very soon completely reunite (v. PI. 2). On the left side
only single and more disconnected bundles thrust up through
the muscle. Just in front of the m. nasalis a small portion of the
muscle appears between m. nasalis and the pars rimana m. buc-
cinatorii (v. PI. 1), but then, for a length of 15—20 cm along
the trunk, it is again covered by the pars rimana. On the rest
of the proboscis, unto the extreme distal end of this organ, the
portio inferior lies quite superficially, covered only by the fascia,
reaching to about the middle of the lateral face of the trunk
(comp. PI. 2 and the transverse section PL 14, fig. 2).

The portio superior is strongly developed. It extends to the
median line and here fuses with the corresponding muscle of
the other side, so that they together form a broad, powerful
muscle, which from the front stretches down the dorsal, and
partly the lateral, face of the trunk to its extreme distal end (PI. 1).
The superior portion arises from the frontal surface, rather far
back, with a large and broad aponeurosis, which may distinctly
be traced to the posterior part of the frontal bones, where it is
intimately connected with the periosteum. Laterally this aponeurosis
grows shorter and the origin stretches down the frontal
and the maxillary bone just in front of the orbit, where it extends
downwards till about level with the origin of the lig. palpebrale,
so that it is here separated from the portio inferior by a rather
broad interval, which is cuneate anteriorly and filled with adipose
tissue. In the space in front of the eye the origin of the portio
superior is covered by the nasolabialis. On the frontal surface,
where the entire muscular body arises from the aponeurosis
with a bowed, posteriorly convex line, the upper part thereof
becomes fleshy on the level of the posterior angle of the eye,
whereas the lower part thereof is fleslry almost from its origin.

We have no doubt that the muscle described here as the
m. maxillo-labialis of the Elephant, really corresponds to this muscle
in other Mammals, although indeed, in many respects, it shows
considerable deviations from the account of this muscle in the
Mammals, given in the General Part; deviations which, however,
may be explained by the share this muscle has in forming the
trunk. The place of the origin in relation to the m. nasolabialis
decidedly shows that the muscle belongs to a deeper layer
than the orbicularis-group; and as to origin and insertion the
portio inferior is, in the main, as the corresponding muscle in
the Mammals investigated, in which it arises from the maxillary
bone laterad of the foramen infraorbitale and inserts itself into
the lateral circumference of the nostril. Finally, it must be mentioned
that relations between the portio inferior and the m. nasalis
similar to those of the Elephant are found for instance in the
Ungulates, in which the portio inferior is to a still larger extent
traversed by the m. nasalis than in the Elephant. In the Ungulates
, indeed, the muscle radiating in front like a fan offers a

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