Chap. IY. 
MANNER OF DEVELOPMENT. 
129 
feet or imperfect, yet in this latter case manifestly of 
a transitional nature. Certain variations are more com- 
mon in man, and others in woman, without our being 
able to assign any reason. Mr. Wood, after describing 
numerous cases, makes the following pregnant remark : 
“ Notable departures from the ordinary type of the 
“ muscular structures run in grooves or directions, which 
“ must be taken to indicate some unknown factor, of 
“ much importance to a comprehensive knowledge of 
“ general and scientific anatomy .” 48 
That this unknown factor is reversion to a former 
state of existence may be admitted as in the highest 
degree probable. It is quite incredible that a man 
should through mere accident abnormally resemble, in 
no less than seven of his muscles, certain apes, if there 
had been no genetic connection between them. On the 
other hand, if man is descended from some ape-like 
creature, no valid reason can be assigned why certain 
muscles should not suddenly reappear after an interval of 
many thousand generations, in the same manner as with 
horses, asses, and mules, dark-coloured stripes suddenly 
reappear on the legs and shoulders, after an interval of 
hundreds, or more probably thousands, of generations. 
These various cases of reversion are so closely related 
48 The Rev. Dr. Haughton, after giving (‘ Proc. R. Irish Academy,’ 
June 27, 1864, p. 715) a remarkable case of variation in the human 
flexor pollicis longus , adds, “This remarkable example shews that man 
“ may sometimes possess the arrangement of tendons of thumb and 
“ fingers characteristic of the macaque ; but whether such a case should 
“ be regarded as a macaque passing upwards into a man, or a man 
“ passing downwards into a macaque, or as a congenital freak of 
“ nature, I cannot undertake to say.” It is satisfactory to hear so 
capable an anatomist, and so embittered an opponent of evolutionism, 
admitting even the possibility of either of his first propositions. Prof. 
Macalister has also described (‘ Proc. R. Irish Acad.’ vol. x. 1864, p. 
138) variations in the flexor pollicis longus, remarkable from their rela- 
tions to the same muscle in the Quadrumana. 
YOL. I. 
K 
