19 
Mammals generally. 
Ear-muscles in Placentals with a scutellum. Do .in Marsupials. 
20 
the auricular portion of the sphincter profundus; the fibres have a 
predominant longitudinal direction. Sometimes it arises almost 
only from the scutellum (Elk), in others it arises only from the 
face farther down (Dog, PI. 12; Cow); in the Horse it has been 
divided into two quite separate muscles (»adductor inferior* * * and 
;>adductor externus« of the Veterinarians), of which only the up¬ 
per takes its origin from the scutellum. In the Swine (PL 9) the 
muscle is divided into three small portions, which together form 
a three-lobed fan, and of which only the uppermost takes its 
origin from the scutellum; the front ends of the others are con¬ 
nected with the ends of the fibres of some of the scutularis- 
bundles, of which a large part do not reach the scutellum in the 
Swine. This is a secondary connection (comp, the Marsupials). 
c. Musculus temporo-auricularis. 
The m. temporo-auricularis') (PI. 15, fig. 5) is a narrow, of¬ 
ten rather long muscle, which has its place along the cartilagi¬ 
nous meatus and inserts into the anteron 5, below the rotator. 
It takes its origin sometimes from the lower jaw (Dog, Rabbit), 
sometimes from the bony meatus (Horse), sometimes from the 
posterior end of the zygoma (Elk, Swine). The muscle is quite 
independent and presents no connection with other muscles; it 
might be thought probable that it is to be derived from one of 
the two great muscular complexes described above, but there is 
no indication of the way in which it may have arisen from any 
of them. 
d. Muscles which both arise from and insert into 
the auricular cartilage. 
The m. anteri sexti — = m. helicis major + minor horn. — 
(PL 15, fig. 4; PL 12) is a small muscle lying near the anterior 
border of the ear before the anteron 6; sometimes it arises from 
the anteron 5 and inserts into the anteron 7 (Dog, Swine); in 
others it takes its origin from the posteron 4 or tragus (Horse, Elk). 
Dog. Lies on the concave side of the auricle, near the an¬ 
terior border in the furrow before the anteron 6, taking its origin 
from the proximal part of the anteron 5 and inserting into the 
proximal margin of the anteron 7. 
Rabbit. Lies along the very elongated anteron 6 on the cor¬ 
responding place as in the Dog. It is a long thin muscle. 
Swine. Arises from the anteron 5 and inserts into the an¬ 
teron 7, lying near the anterior margin — as in the Dog. But 
in the Swine, where the muscle is rather strong, there is further¬ 
more a portion developed, intimately connected with the first 
described, taking its origin from the margin of the incisura an¬ 
terior 4. 
Horse. Takes its origin from the posteron 4 (tragus) and lies 
in the furrow outside the anteron 6, into which furrow it is 
also inserted. 
Elk. A rather broad muscle lying on the concave side of 
the auricle proximad of the anteron 6 and taking its origin as 
in the Horse from the posteron 4. 
M. posteri septimi — =m. antitragicus horn. — (PL 15, fig. 4; 
PL 9). Of the animals examined by us we have only found this 
muscle in the Dog, Rabbit and Swine (PL 9). In all these the 
muscle inserts into the proximal margin ol the posteron 7, which 
in these animals is well developed; sometimes the insertion ex¬ 
tends somewhat on the external (Dog) or internal (Swine) face 
of the posteron. As to the origin of the muscle, this is variable. 
In the Swine it arises from the margin of the antitragus and 
from the distal margin of the posteron 5. In the Dog it arises 
from the proximal margin of the posteron 5 and from the con¬ 
vex surface of the concha, but not from the antitragus. In the 
Rabbit it arises only from the convex surface of the concha. (In 
man it arises from the antitragus and goes to the posteron 7)"). 
M. fissuralis (PL 15, fig. 4) takes its origin from the posteron 4 
(tragus) and inserts into the anteron 5. 
Dog. Takes its origin from the inflected margin of the tragus 
and inserts into the concave surface of the anteron 5. 
') Of the Veterinarians falsely named m. tragicas and homologized with the muscle 
of this name of man, which is quite another. 
*) Qnain, Anatomy, Vol. 3, Part 3, 10. Ed. p. 75. 
Rabbit. Covered by the m. trago-anterus and the adductor 
inferior. It is a rather strong muscle, taking its origin from the 
proximal part of the tragus and inserting into the proximal part 
of the anteron 5. The proximal part of the muscle, which at the 
insertion is confluent with the rest, is a long slender muscle 
taking its origin from the bony meatus. 
Horse. A short rather strong muscle going between the tra¬ 
gus and the anteron 5, which overlaps the tragus. 
Elk and Swine (PL 9). Arises from the surface of the tragus 
and inserts into the margin of the anteron 5. 
We think this muscle is the true homologue of the m. tra- 
gicus of man. This muscle has its place on the tragus and some¬ 
times ‘) it sends some bundles to the »spina helicis*, the homo¬ 
logue of the anteron 5. 
The m. trago-anterus we have only found in the Dog (PL 9) 
and Rabbit. In the Dog it arises with three slips: one takes its 
origin from the outside, near the proximal border, of the tragus; 
another from the outside of the posteron 3. the third from the 
ear-cartilage between the posteron 2 and the anteron 2; all insert 
into the anterior margin of the anteron 5. In the Rabbit it is a 
very broad, short muscular band going from the verj* elongated 
lateral margin of the tragus to that part of the anterior margin 
of the ear which in the Rabbit represents the margin of the an¬ 
teron 5. 
In the Rabbit alone we have found a muscle, which covers 
the fissure between the antitragus and the posteron 5, a layer of 
transverse-oblique muscular fibres going from the antitragus to 
the posteron 5. We propose for this muscle the name: m. anti- 
trago-posterus. 
Besides these muscles there may, on the convex surface of 
the auricle, be present tracts of muscular fibres. They are called 
m. transversi and obliqui and the direction of the generally short 
fibres may be either longitudinal or transverse. In the Dog the 
above-described m. posteri septimi is continued by such a muscu¬ 
lar tract across the auricle. 
B. The ear-muscles of the 
Marsupials. 2 ) 
The facts surveyed in the preceding part, with regard to the 
ear-muscles of the Placentals, are better understood if the ear- 
muscles of the Marsupials are also taken into consideration. 
In Didelphys (Pl. 15, fig. 3; fig. A) there are two large lamelli- 
form ear-muscles lying on the head above and in front of the 
ear, from the eye to the neck; the two muscle-plates overlap one 
another a little, the anterior being external. The anterior muscle, 
the scutularis, sends off a pars transiens, which segregating from 
the rest of the muscle is inserted into the anteron 7; it entirely 
resembles the muscular portion of the same name in the Placen¬ 
tals. The rest of the muscle is continued into a rather narrow 
but thick muscular body, lying directly above the ear-conch, 
which gradually grows narrower and is inserted into the arched 
surface of the ear-conch (PL 15, fig. 3, scutularis, a). This part of 
the muscle is intimately connate with the other great muscle-plate, 
which it overlies. We think this narrow terminal part of the 
scutularis corresponds to the levator brevis of the Horse and other 
animals; like it, it is inserted into the auricle near the inser¬ 
tion of the auriculo-occipitalis, which in Didelphys here overlies 
it. This is not the case in the Horse and Elk, the auriculo-occi¬ 
pitalis not extending so far on the auricle as in Didelphys. 
The other large, lamelliform, muscle of Didelphys corresponds 
to the auriculo-occipitalis + the postauricularis of the Placentals; 
which two muscles are still continuous in Didelphys; moreover, 
posteriorly, this great muscular plate is continued in such a man¬ 
ner into the plalysma behind the ear that it has quite the ap¬ 
pearance of a forward continuation of the last-named muscle, the 
fibres of which here have the same direction as the neighbouring 
fibres of the auriculo-occipitalis -f postauricularis; dorsally a na¬ 
tural limit does not exist. The muscular plate may be divided 
into three portions, which dorsally are continuous, but vent rally 
are more or less separated through splits having a dorso-venlrad 
J ) Henle, Eingeweidelehre, 2. Aufl. p. 757. 
2 ) In this group a scutellum is not developed, 
