210 A BOOK-LOVER'S HOLIDAYS 



ages. Moreover — in exact analogy with other 

 divisions of time, all of which, however useful, 

 are essentially artificial — we must constantly 

 remember that the perspective changes utterly 

 with the point of view. All paleontological terms 

 of time are necessarily terms chiefly of con- 

 venience, which have and express a real in- 

 trinsic value, but which cannot be sharply 

 defined. Miocene, Pliocene, Pleistocene, and 

 Recent are such terms. They are arbitrarily 

 chosen bits of terminology to express successive 

 stages of the world's growth, and therefore 

 successive and varying faunas. They are not 

 equivalent in time to one another; the more 

 remote the age from our own the greater is the 

 length of time we include therein. '* Recent" 

 denotes a short period of time compared to 

 "Pleistocene," and "Pleistocene" a short period 

 compared to "Phocene." If there are on this 

 earth intelligent beings at a time in the future 

 as remote from our day as our day is from the 

 Pliocene, they will certainly consider "Recent" 

 and "Pleistocene" as one short period. All the 

 beast faunas and all the human cultures from 

 the eras of the chinless Heidelberg and Pilt- 

 down men to our own time will seem in that 

 remote perspective practically contemporane- 

 ous. Similarly, when we try to grasp Ufe as 



