MUSCULAR SYSTEM 109 
The helicis major (Fig. 71, m.h’.) and the tragicus (m.t.) 
(the second of which is often wanting), are to be derived from 
the scutulo-auriculare (a portion of the depressor helicis, Ruge), 
found in those Mammals which still possess a free and movable 
scutulum. The helicis minor (m.h”.), antitragicus (m.a’.), and the 
ineisure Santorini, which belong to the cartilaginous wall of the 
external auditory meatus, are the proper ear muscles (auriculares 
propri), and related to the principal cartilages and the pinna 
alone. 
Taking all the facts into consideration, this intrinsic muscu- 
lature of the pinna, which is no longer under the control of the 
will, must be considered as the vestige of a primitive apparatus 
functional either for the opening and closing, or for the widening 
and narrowing of the auditory funnel and the external auditory 
passage (cf. chapter on the auditory organ, infra). 
4. To the fourth class belong those mimetic muscles which 
have undergone the greatest degeneration, 7.e. those which have 
become transformed into tendinous or membranous structures 
(fasciz). For example, the auriculo- (temporo-) labialis muscle of 
the Lemuroids (cf. Figs. 68 and 69) has, in Man, been replaced 
by the fascia temporalis superficialis, and the sphincter colli 
muscle by the fascia parotideo-masseterica. A great part of the 
human epicranial aponeurosis (galea aponeurotica), further, 
consists of muscle bundles of the occipitalis transformed into 
tendons. 
[It is interesting to note that the power of contracting the platysma, the 
ear muscles, and others not normally under the control of the will, has been 
observed in a few cases to go hand in hand with that of a voluntary con- 
trol of the heart’s action. |! 
MUSCLES OF THE LIMBS 
The palmaris (=p. longus) and its homologue in the hind- 
limb, the plantaris, are time honoured (and certainly among the 
best) examples of the gradual degeneration of a muscle. The 
degeneration of the former has not yet proceeded as far as that of 
the latter, as is most evident in the fact that while the palmaris 
still reaches the palmar fascia of the hand, the plantaris only in 
exceptional cases becomes connected with the homologous plantar 
fascia of the foot, and in doing so regains its former significance 
as a flexor of that organ. 
The plantaris must therefore, as an original flexor, have 
1 (Cf. E. A. Pease, Boston Med. and Surg. Jour., 30th May 1889.] 
