1 88 SCIENCE SKETCHES. 



say that he is the very image of his father. My 

 neighbor on the left shows a wider divergence, but 

 then he too is evidently an Anglo-Saxon. Angle 

 or Saxon, we are all of one blood, not many gen- 

 erations back. A little farther away the whole 

 Aryan race becomes one ; and in Adam we are all 

 one, even with our poor relations, the negro and 

 the Chinaman. If we knew them all, the chain of 

 ancestors would be as unbroken as the chain which 

 connects the boy and the man, or the chain which 

 joins the American of to-day with his Angle and 

 Saxon and Aryan ancestors. Where homologies 

 exist there is somewhere the elements of a genea- 

 logical tree. 



But still poorer relations we have in numbers, 

 and they too carry on their faces the unmistak- 

 able evidence of kinship by blood. In every bone 

 and muscle my dog shows his likeness to me, and 

 even in every function of his feeble little brain the 

 resemblance is apparent. Let me say again, we 

 have no explanation of homology other than that 

 of kinship by blood. This is Darwinism, and this 

 is a lesson of all biological science. There is sub- 

 stantially the same evidence — the same in kind 

 and not much less in degree — for believing that 

 my dog and myself are related by blood in some 

 form of distant cousinship as there is to show a 

 similar relationship between myself and any one 

 of my neighbors about me to-day. History, as de- 

 duced from the registers in our family-Bibles, shows 

 no trace of relationship in either the one case or the 

 other. Our records go back for a few generations 

 only, and the great past Is lost. In either case our 



