41 
Elephant. 
M. rectus nasi. Muscular system of the trunk. 
42 
none were found, whei'eas they were numerous in the ventral 
half. And, moreover, the} 7 proceed some distance down, ventrad 
of the septum, where they partly thrust between, partly pass 
into, the ventral fascicles. 
The next section (PI. 14, fig. 7) is cut just in front of the 
point of the under lip. The radiating fascicles are here seen in 
the dorsal, lateral, and ventral circumference of the nasal tube. 
The lateral and ventral ones are not present in quite so great a 
number as in the second section, and the ventral ones have be¬ 
come longer and run a little more curved ventrad. On the other 
hand, it is to be noted that, in the space from the 2 nd to the 3 rd 
section, a considerable increase of the transverse fascicles has 
taken place. Through the whole height of the septum (which, how¬ 
ever, is not considerable in this place) these fascicles are found, 
and we draw particular attention to the fact that they proceed 
a considerable distance down, below the nasal tubes, where they 
form a close mass of thick, transverse fascicles, which, with their 
ends somewhat turn in a bow, upwards, ending in the connective 
tissue inside the ventral radial fascicles. 
Finally, we come to a section about the middle of the trunk 
(PI. 14, fig. 8): Here we see the radial fascicles from the dorsal, 
lateral, and ventral circumference of the nasal tube as a conti¬ 
nuous, radiating, muscular mass. The ventral fascicles are here 
not much longer than the dorsal ones. Through the septum, and 
below it, the transverse fascicles are found. In the septum itself, 
they are numerous, whereas much fewer are found below it than 
in the former section. This likeness in the main appears again 
in the sections throughout the distal half of the trunk; the fas¬ 
cicles, however, gradually decreasing more and more in length. 
We must yet add that we have not contented ourselves with 
simply cutting through the trunk in the places described, but 
have in reality made a great number of sections throughout 
its whole length. By this means we have found that the transi¬ 
tion from the likeness offered by one section to that offered by 
another is quite gradual. 
Now, if by means of the sections described, we try to form 
one picture of the whole m. rectus nasi the result will be as fol¬ 
lows: Through the whole length of the trunk there is a large 
system of radial fascicles. They arise from the mucous membrane 
of the nasal tube radiating thence dorsad, laterad, and ventrad. 
The dorsal and ventral fascicles bend into the septum, and run 
here from one nasal tube to the other. In the details there is 
some variation in the length and more or less close arrangement 
of the fascicles; this is especially the case with the proximal half 
of the trunk and is evidently in close connection partly with 
the alteration of the form of the lumen of the nasal tube partly 
with its situation in the section, and partly with the relations of 
the trunk to the neighbouring parts. As to the last it must espe¬ 
cially be remarked that the ventral fascicles, in the space where 
the trunk overlies the intermaxillary bone, insert into the bone, 
which is not otherwise the case with the rectus nasi generally. 
Further it must be remarked that from about the anterior mar¬ 
gin of the intermaxillary bone and farther down through the 
rest of the trunk the transverse fascicles proceed down in the 
portion below the nasal tubes and are particularly numerous in 
the proximal part of the trunk. 
As to the insertion of the fibres we see in the sections that 
the dorsal and lateral fibres pass into thin, short tendons that 
thrust up between the fascicles of the m. maxillo-labialis (PL 14, 
fig. 2) and insert themselves into the deep face of the fascia out¬ 
side this muscle. The ventral fascicles of the basal part of the 
trunk are inserted, as described, into the intermaxillary bone. On 
the rest of the trunk by far the greater number end in the con¬ 
nective tissue inside the portio supralabialis, whereas a smaller 
number may be followed somewhat outwards into the connective 
tissue between the fascicles of this muscle (PI. 14, fig. 2). 
Further, our examinations show that the rectus-fascicles are 
arranged very regularly in longitudinal rows, separated from 
each other by adipose connective tissue. On the whole dorsal 
and lateral circumference of the trunk — that is, in the whole 
extent of the m. maxillo-labialis — these rows of fibres pass into 
low aponeuroses that extend up through the m. maxillo-labialis 
(PI. 2) and so become inserted into the fascia — the thin short 
tendons mentioned above in the description of the section being in 
reality aponeuroses, each aponeurosis being common for one row 
of fascicles. We have already described these aponeuroses in 
full detail, when dealing with the m. maxillo-labialis. And what 
is said of their arrangement, and course, also applies to the rows 
of fibres. Here we have only one addition to make: Between the 
rows of the fibres with their aponeuroses grooves are formed; 
about the inner half of each of these groves is filled with adipose 
tissue, so that only a little more than the outer half is occupied 
by the fascicles of the m. maxillo-labialis (PI. 14, fig. 2). 
The previous authors (v.e.g. Miall and Greenwood, Harrison 1 ), 
Watson) have, of course, all seen the radial fascicles; but as to 
the examination, and description thereof it is as with their de¬ 
scription of the buccinator group: most deficient. 
If we survey the whole muscular system of the trunk, we 
find it contains, first longitudinal and oblique fascicles, the latter 
moreover arranged in two crossing layers. The longitudinal las- 
cicles, m. maxillo-labialis, occupy the dorso-lateral circumference; 
the oblique fascicles, the pars rimana and the pars supralabialis 
m. buccinatorii, the ventro-lateral. In this arrangement of the fas¬ 
cicles lies the explanation of the extremely free mobility of the 
trunk. The longitudinal muscles, »the levatores proboscidis« of 
previous authors, produce the raising movements of the trunk, 
the amplitude of which, as is well known, is so great that the 
trunk may be raised up so as to rest upon the upper surface of 
the head and the neck. This movement is, in the main, made 
by the portio superior m. maxillo-labialis, whereas a onesided 
contraction of the portio inferior, which lies chiefly on the la¬ 
teral face of the trunk, will produce a lateral motion. A simul¬ 
taneous activity of the oblique muscles, the »depressores pro- 
boscidis« of previous authors, will produce either a lowering of 
the trunk, or, (by simultaneous relaxation of the longitudinal 
muscles) the well-known rolling up thereof against its ventral 
face, whereas a onesided contraction will evidently be instru¬ 
mental in the lateral motion. By a combination of these move¬ 
ments the trunk will be able to adjust itself in all directions. 
For the sake of comparison we may invite attention, for a mo¬ 
ment to the muscles of the tail of Mammals, which it is hardly 
necessary to remind our readers, is also most freely movable. 
The muscles of this organ are most familiar iu the domestic 
Mammals, where they are, primarily, arranged longitudinally, 
both on the dorsal and the ventral faces: and these muscles first 
produce the raising and depressing movements. The former may 
be carried so far that the tail is rolled up against its dorsal 
face 2 ), but these longitudinal fascicles can also, certainly by one¬ 
sided activity, — eventually supported by the small mm. inter- 
transversarii that span from one proc. transversus to the next — 
produce lateral motions. But these are, in the main, due to a 
pair of oblique muscles that, one on each side, extend from the 
pelvis to the anterior vertebrae of the tail (the m. coccygeus of 
the Veterinarians). The tail then, can execute many of the same 
movements which we have described in the proboscis: but in 
the more special arrangement of the muscles there is however 
an essential difference. The muscular mass, the fleshy mass, is 
in the tail chiefly gathered round its »roots, i. e. its proximal 
part; certainly the muscles extend for a considerable distance 
down the tail (some muscles almost to its very point), but distad 
the fleshy mass soon greatly decreases. The great range of move¬ 
ment of which the tail is capable, is then produced in such a 
way that from the muscular mass there arise long thin tendons 
that run far out on the tail, often passing over several vertebrae 
before they are inserted. On the proboscis the case is otherwise. 
The fleshy mass here extends to its very tip, being the chief 
content of the proboscis, which by its immense contents of fibres, 
can throw enormous force into its motions. 
*) The paper quoted p. 43. 
2 ) There are, however, also Mammals that can roll up the tail against the 
ventral face. 
6 
