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37 Elephant.

closely connected with the skin. On the proximal part of the
trunk the fascicles reach highest up, almost to the very dorsal
face, here covering part of the m. maxillo-labialis; but in its
further course the muscular body grows narrower, the line of
insertion does not extend so far dorsad on the lateral face of
the trunk, where it only reaches up to the lateral margin of the
maxillo-labialis, corresponding to about the middle of the lateral
face of the trunk (PI. 1). At the distal end, where its fascicles are
almost longitudinal, the muscular body has become quite narrow,
and united with the maxillo-labialis so intimatelv that the limit
between them can hardly be indicated (PI. 1).

If the pars rimana is removed, there is found under it a continuous
layer of fascicles throughout the whole length of the
trunk, and crossing the direction of the fascicles of the pars rimana
(PI. 2). This deep oblique layer takes its origin from the front
end of the intermaxillary bone and from the inside of the base of
the incisor; but from this point the line of origin proceeds downwards
upon the proboscis for the whole length — along the margin
of the maxillo-labialis, the fascicles arising from inside the lateral
border of this muscle (PI. 14, fig. 2). This deep oblique layer is
the pars supralabialis m. buccinatorii of the Elephant. Indeed, it does
not form any direct continuation of the buccinator, its origin
appearing with a certain independence, but something similar
we have also found elsewhere e. g. in the Tapir. And the manner
in which the hinder end of the muscle takes its origin from the
intermaxillary bone and the position of the muscle in relation
to the pars rimana are those of the pars supralabialis (comp.
also the pars supralabialis of the Elk, where sometimes an anterior
portion of the fascicles of the supralabialis also does not
take its origin from the bone).

As to the details of the pars supralabialis in the Elephant
we shall further mention the following: From the whole line of
origin the fascicles run obliquely forwards (distad), then turning
in a semicircle on to the ventral face of the trunk (PL 14, fig. 10).
Thus they cross the fascicles of the pars rimana and this crossing
is distinctly pronounced throughout the whole course of the muscles.
On the basal part of the trunk where, as we have said, the fascicles
of the pars rimana turned very steeply on to the dorsal
face almost approaching to the transverse direction, the fascicles
of the pars supralabialis are found running only a little obliquely
forwards approaching most to a longitudinal direction (comp.
PL 1 and 2, PL 14, fig. 9 and 10). While the fascicles of the pars
rimana in their further course took a less and less oblique direction
, the reverse obtains with the fascicles of the pars supralabialis
as they take a steeper and steeper course, on the distal
part of the trunk closely approaching to the transverse direction.
The fascicles of the pars supralabialis are inserted into the deep
face of the aponeurosis covering the ventral face of the trunk
and serving as origin of the pars rimana, and reach almost to
the very median line. So then, onLy a narrow stripe of the aponeurosis
remains free between the lines of insertion for the right
and left pars supralabialis (PL 14, fig. 2 and 10).

The m. nasalis (PL 1—4) arises from the intermaxillary bone
behind, above and inside the base of the incisor. The foremost
rather thick part (PL 3), which takes its origin from inside the
base of the incisor, extends obliquely upon the proximal part of
the ventral side of the proboscis, covered by the basal portion of
the pars supralabialis m. buccinatorii; the ends of its fibres are directed
upwards and forwards. The rest of the muscle is as usual
situated on that part of the face lying above the upper lip. It
forms a large mass of rather short and thick fascicles; in detail
there is some difference between the two halves of the head,
examined by us, and this fact makes it desirable to mention each
separately. In the right half (PL 1, 2 and 3) the fascicles arise
remarkably regularly, in several rows, one above the other; altogether
5 such could be dissected out, the 2d—4th of which are
seen in PL 2, whereas the fifth is figured in PL 3. The 1st (undermost
) row arises from the ventral face of the intermaxillary consisting
of rather a considerable number of fascicles that run
transversely outwards, then turning in a semicircle upwards in
the upper lip, where they partly thrust out above, partly cross

Buccinator-group. 38

in between, the fascicles of the pars rimana (in PL 4 this 1st row
is figured on the left half). From each of the lines of origin of
the following 4 rows the fascicles radiate upwards like a fan,
and as the lines of origin lie higher and higher up and the fascicles
of each row have about the same length, the fascicles appear
quite regularly imbricated, the short, pointed, tendinous
ends of the fascicles of one rowr projecting somewhat above those
of the one lying beneath. In the 4th rowr, however, the fascicles
are so long that they quite cover the 5th one. The fascicles of
the 1st—4th row are inserted into the skin of the upper lip,
and of the root of the trunk. The m. nasalis, as mentioned,
crosses up through the portio inferior of the maxillo-labialis, and
on the right side this crossing is done in such a way that an
anterior, rather broad, fascicle of the 4th row thrusts up through
the portio inferior so that this, as it were, is divided into two
portions which, however, soon are connected again (PL 2). —
The 5th row (PL 3) arises from the dorsal face of the intermaxillary
, and forms the most important part of the whole muscle.
It measures about 2 cm in width (thickness). The fascicles radiate
upwards to the fascia on the trunk, where they are inserted,
but are during their course crossed by the radial fascicles (m. recti,
v. infra) of the trunk, which are arranged like leaves and project
between the fascicles of this row. It is a very intimate crossing
that is formed bv these two muscles since in each interval be-
tween the fascicles of the 5th row, a plate of radial fascicles
projects (PL 3). The 5th row is anteriorly continued by the foremost
part of nasalis, mentioned above, which arises from inside
the base of the incisor.

In the left half (PL 4) of the head examined as to all essential
points the same is found as in the right half, but the fascicles
neither arise, nor are arranged, so regularly as on that side;
the whole forms a more continuous muscular mass consisting of
rather coarse fascicles with plenty of intramuscular adipose connective
tissue, so that each fascicle ma}' easily be dissected out.
On this side there is also a crossing of the portio inferior m.
maxillo-labialis but with more scattered and fewer fascicles, than
on the right side. The relation to the radial fascicles is the same
as on the other side. The most ventral fascicles penetrate the
pars rimana of the upper lip; in PL 4 the ends of these bundles
are distinctlv seen.

The m. mentalis (PL 1—4, espec. 3 and 4) forms a very considerable
mass of fascicles that in the usual way arise from the
anterior part of the lower jaw, radiating to the skin of the same.
Posteriorly the muscle intimately joins the superficial longitudinal
fascicles of the m. buccinatorius — so intimately that, in reality,
they form an immediate continuation of these fascicles. This
is distinctly seen in PL 4, where the ends of the fascicles of
the mentalis are seen thrusting out from the connective tissue
in the under lip. The fascicles radiate towards the skin, and are
in the main arranged similarly to the fascicles of the m. nasalis,
that is, in rows (v. the cut in the under lip in PL 3).

The buccinator-group has been examined most deficiently by
previous authors. In the paper of Watson there is a very short
and rather vague description of the m. buccinatorius itself. Miall
and Greenwood evidently have not examined this group at all,
as they content themselves with quoting Watson. As to the
muscles of the trunk; previous authors have, of course, all found
the two oblique layers, just as the}' also all of them know the
longitudinal (m. maxillo-labialis) and the radial fascicles; but the
description shows, clearly enough, that they have by no means
dissected with the necessary minuteness. The consequence of
this, indeed, is that their conception of the whole buccinator-
group in the Elephant is essentially different from ours in nearly
all respects. None of them have realized the intimate connection
of the muscles of cheek, lip, and trunk, but describe these portions
separately as independent muscles. To limit ourselves to
Miall and Greenwood, whose investigations evidently are the
most thorough hitherto given, we find that they acquiesce entirely
in Guvier's old statement; according to which, there is a
superficial layer with fascicles running more or less longitudinally,
and a deep layer with radial and transverse fascicles. Again, the
»longitudinal muscles« are on each side divided into an »ante-
rior«, a »lateralis« and a »posterior« one. The anterior or the
»levator proboscidis« is our portio superior m. maxillo-labialis.
The »posterior« muscle or »depressor proboscidis«, consisting of
2 layers of oblique fascicles, arranged in crossing direction, evidently
corresponds to our pars rimana and pars supralabialis.

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