128 
THE DESCENT OF MAN. 
Part 1. 
these it serves exclusively to aid the male in the act 
of reproduction. 
Mr. J. Wood, in bis valuable series of papers , 45 has 
minutely described a vast number of muscular varia- 
tions in man, which resemble normal structures in the 
lower animals. Looking only to the muscles which 
closely resemble those regularly present in our nearest 
allies, the Quadrumana, they 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 clavi- 
cultv ,” such as is found in all kinds of apes, and which 
is said to occur in about one out of sixty human sub- 
jects . 45 Again, this man had “a special abductor of 
“ the metatarsal bone of the fifth digit, such as Pro- 
“ fessor Huxley and Mr. Flower have shewn to exist 
“ uniformly in the higher and lower apes.” The hands 
and arms of man are eminently characteristic structures, 
but their muscles are extremely liable to vary, so as to 
resemble the corresponding muscles in the lower ani- 
mals . 47 Such resemblances are either complete and per- 
45 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 tho Quadrumana. The following references relate to the few point* 
touched on in my text : Proo. Royal Soc. vol. xiv. 1865, p. 379-384 , 
vol. xv. 1866, p. 241, 242 ; vol. xv. 1S67, p. 544 ; vol. xvi. 18CS, p. 524. 1 
may here add that Dr. Murie and Mr. St. George Mivnrt have shewn 
in their Memoir on the Lomuroidea (‘Transact. Zoolog. Soc.’ vol- vn ' 
1869. p. 96), how extraordinarily variable some of the muscles are m 
these animals, tho lowest members of the Primates. Gradations, als°i 
in the muscles lending to structures found in animals still lower in 
the scale, are numerous in the Lemuroidea. 
48 Prof. Maculistcr in ‘Proe. R. Irish Academy,’ vol. x. 1S6S, p. 1-'*' 
47 Prof. Maealiater (ibid. p. 121) has tabulated his observations, an 
finds that muscular abnormalities arc most frequent in the forearms 
secondly in the face, thirdly in the foot, &c. 
