NATURAL SELECTION, ETC. 101 



tlie same account. Mammoths, mastodons, and Irish 

 elks, now extinct, must have lived down to human, if 

 not almost to historic times. Perhaps the last dodo 

 did not long outlive his huge ISTew Zealand kindred. 

 The auroch, once the companion of mammoths, still 

 smwives, but owes his present and precarious existence 

 to man's care. J^ow, nothing that we know of forbids 

 the hypothesis that some new species have been inde- 

 pendently and supernaturally created within the period 

 which other species have survived. Some may even 

 believe that man was created in the days of the mam- 

 moth, became extinct, and was recreated at a later date. 

 But why not say the same of the auroch, contempo- 

 rary both of the old man and of the new ? Still it is 

 more natural, if not inevitable, to infer that, if the 

 aurochs of that olden time were the ancestors of the 

 aurochs of the Lithuanian forests, so likewise were the 

 men of that age the ancestors of the present human 

 races. Then, whoever concludes that these primitive 

 makers of rude flint axes and knives were the ancestors 

 of the better workmen of the succeeding stone age, 

 and these again of the succeeding artificers in brass and 

 iron, will also be likely to sujDpose that the Eqxtus and 

 Bos of that time, different though they be, were the 

 remote progenitors of our own horses and cattle. In 

 all candor we must at least concede that sucn consid- 

 erations suggest a genetic descent from the drift period 

 down to the present, and allow time enough — if time is 

 of any account — for variation and natural selection to 

 work out some appreciable results in the way of diver- 

 gence into races, or even into so-called species. What- 

 ever might have been thought, when geological time 



