386 GENEEAL SUMMAKY Pakt 11. 



he retains, and the abnormal reversions to which he 

 is occasionally liable, — are facts which cannot be dis- 

 puted. They have long been known, but until recently 

 they told us nothing with respect to the origin of 

 man. Now when viewed by the light of our know- 

 ledge of the whole organic world, their meaning is 

 unmistakeable. The great principle of evolution stands 

 up clear and firm, when these groups of facts are con- 

 sidered in connection with others, such as the mutual 

 affinities of the members of the same group, their 

 geographical distribution in past and present times, 

 and their geological succession. It is incredible that 

 all these facts should speak falsely. He who is not 

 content to look, like a savage, at the phenomena of 

 nature as disconnected, cannot any longer believe that 

 man is the work of a separate act of creation. He will 

 be forced to admit that the close resemblance of the 

 embryo of man to that, for instance, of a dog — the con- 

 struction of his skull, limbs, and whole frame, indepen- 

 dently of the uses to which the parts may be put, on 

 the same plan with that of other mammals — the occa- 

 sional reappearance of various structures, for instance 

 of several distinct muscles, which man does not nor- 

 mally possess, but which are common to the Quadru- 

 mana — and a crowd of analogous facts — all point in 

 the plainest manner to the conclusion that man is the 

 co-descendant with other mammals of a common pro- 

 genitor. 



We have seen that man incessantly presents indi- 

 vidual differences in all parts of his body and in his 

 mental faculties. These differences or variations seem 

 to be induced by the same general causes, and to obey 

 the same laws as with the lower animals. In both 

 cases similar laws of inheritance prevaiL Man tends to 

 increase at a greater rate than his means of subsistence ; 



