CHAP. XII. 



GEOLOGICAL PRINCIPLES. 



133 



volcanoes. The other case is that of rude stone imple- 

 ments discovered by a geologist of the Indian Survey in 

 Burma in deposits which are admitted to be of at least 

 Pliocene age. In both these cases the evidence is dis- 

 puted by some geologists, who seem to think that there is 

 something unscientific, or even wrong, in admitting evi- 

 dence that would prove the Pliocene age of any other 

 animal to be equally valid in the case of man. There 

 is assumed to be a great improbability of his existence 

 earlier than the very end of the Tertiary epoch. But 

 all the indications drawn from his relations to the anthro- 

 poid apes point to an origin far back in Tertiary time. 

 For each one of the great apes the gorilla, the chim- 

 panzee, the orang, and even the gibbon resemble man 

 in certain features more than do their allies, while in 

 other points they are less like him. Now, if man has 

 been developed from a lower animal form, we must seek 

 his ancestors not in the direct line between him and any 

 of the apes, but in a line toward a common ancestor to 

 them all; and this common ancestor must certainly date 

 back to the early part of the Tertiary epoch, because in 

 the Miocene period anthropoid apes not very different 

 from living forms have been found fossil. 



There is therefore no improbability whatever in the 

 existence of man in the later portions of the Tertiary 

 period, and we have no right, scientifically, to treat any 

 evidence for his existence in any other way than the evi- 

 dence for the existence of other animal types. 



It has been argued by some writers that, as no other 

 living species of mammal goes back farther than the 

 Newer Pliocene, therefore man is probably no older. 

 But it is forgotten that the difference of man from the 



