146 MAN AND THE LOWER ANIMALS. n 



leading us insensibly from the crown and summit 

 of the animal creation down to creatures, from 

 which there is but a step, as it seems, to the low- 

 est, smallest, and least intelligent of the placental 

 Mammalia. It is as if nature herself had fore- 

 seen the arrogance of man, and with Roman 

 severity had provided that his intellect, by its 

 very triumphs, should call into prominence the 

 slaves, admonishing the conqueror that he is but 

 dust. 



These are the chief facts, this the immediate 

 conclusion from them to which I adverted in the 

 commencement of this Essay. The facts, I be- 

 lieve, cannot be disputed; and if so, the conclusion 

 appears to me to be inevitable. 



But if Man be separated by no greater struc- 

 tural barrier from the brutes than they are from 

 one another — then it seems to follow that if any 

 process of physical causation can be discovered by 

 which the genera and families of ordinary animals 

 have been produced, that process of causation is 

 amply sufficient to account for the origin of Man. 

 In other words, if it could be shown that the Mar- 

 mosets, for example, have arisen by gradual modi- 

 fication of the ordinary Platyrhini, or that both 

 Marmosets and Platyrhini are modified rami- 

 fications of a primitive stock — then, there would 

 be no rational ground for doubting that man might 

 have originated, in the one case, by the gradual 



