was present. This muscle, therefore, appears to be much more common in
the male than in the female sex; and on the belief in the descent of
man from some lower form, the fact is intelligible; for it has been
detected in several of the lower animals, and in all of these it serves
exclusively to aid the male in the act of reproduction.
Mr. J. Wood, in his valuable series of papers (48. These papers deserve
careful study by any one who desires to learn how frequently our
muscles vary, and in varying come to resemble those of the Quadrumana.
The following references relate to the few points touched on in my
text: Proc. Royal Soc. vol. xiv. 1865, pp. 379-384; vol. xv. 1866,
pp. 241, 242; vol. xv. 1867, p. 544; vol. xvi. 1868, p. 524. I may here
add that Dr. Murie and Mr. St. George Mivart have shewn in their Memoir
on the Lemuroidea ( Transactions, Zoological Society, vol. vii. 1869,
p. 96), how extraordinarily variable some of the muscles are in these
animals, the lowest members of the Primates. Gradations, also, in the
muscles leading to structures found in animals still lower in the
scale, are numerous in the Lemuroidea.), has minutely described a vast
number of muscular variations in man, which resemble normal structures
in the lower animals. The muscles which closely resemble those
regularly present in our nearest allies, the Quadrumana, are too
numerous to be here even specified. In a single male subject, having a
strong bodily frame, and well-formed skull, no less than seven muscular
variations were observed, all of which plainly represented muscles
proper to various kinds of apes. This man, for instance, had on both
sides of his neck a true and powerful levator claviculae, such as is
found in all kinds of apes, and which is said to occur in about one out
of sixty human subjects. (49. See also Prof. Macalister in
Proceedings, Royal Irish Academy, vol. x. 1868, p. 124.) Again, this
man had a special abductor of the metatarsal bone of the fifth digit,
such as Professor Huxley and Mr. Flower have shewn to exist uniformly
in the higher and lower apes. I will give only two additional cases;
the acromio-basilar muscle is found in all mammals below man, and seems
to be correlated with a quadrupedal gait, (50. Mr. Champneys in
Journal of Anatomy and Physiology, Nov. 1871, p. 178.) and it occurs
in about one out of sixty human subjects. In the lower extremities Mr.
Bradley (51. Ibid. May 1872, p. 421.) found an abductor ossis metatarsi
quinti in both feet of man; this muscle had not up to that time been
recorded in mankind, but is always present in the anthropomorphous
apes. The muscles of the hands and arms parts which are so eminently
51