Chap. IV.J MANNER OF DEVELOPMENT. 123 



others the rudimentary ligament was present. This 

 muscle, therefore, appears to be much more common in 

 the male than in the female sex ; and on the principle of 

 the descent of man from some lower form, its presence can 

 be understood ; 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, 45 lias 

 minutely described a vast number of muscular variations 

 in man, which resemble normal structures in the lower 

 animals. Looking only to the muscles which closely re- 

 semble 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 power- 

 ful " levator claviculce" such as is found in all kinds of 

 apes, and which is said to occur in about one out of sixty 

 human subjects. 46 Again, this man had "a special ab- 

 ductor of the metatarsal bone of the fifth, digit, such 

 as Prof. Huxley and Mr. Flower have shown to exist 

 uniformly in the higher and lower apes." The hands and 



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 the Quadrumana. The following references relate to the few points 

 touched on in my text, 'Proc. Royal Soc' vol. xiv. 18G5, pp. 3'79-3S4; 

 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 shown in 

 their Memoir on the Lemuroidea (Transact: Zoolog. Soc.' vol. vii. 1369, 

 p. 96), how extraordinarily variable some of the muscles are in these ani- 

 mals, the lowest members of the Primates. Gradations, also, in the mus- 

 cles leading to structures found in amimals still lower in the scale, aro 

 numerous in the Lemuroidea. 



46 Prof. Macalister in ' Proc. K. Irish Academy,' vul. x. 1868, p. 124. 



