THE PLEISTOCENE OR GLACIAL PERIOD. 513 



In Europe, cave deposits have afforded a very important part of 

 the evidence of man's antiquity, by showing that he was contem- 

 poraneous with a considerable number of animals that have become 

 extinct, and by inherent evidences of age. In America the evidence 

 of the caves is thus far essentially negative in this respect, the 

 relics of man in caves being associated with the living fauna, with 

 perhaps one or two doubtful exceptions. The mammoth and masto- 

 don, as already noted, lived after the last known glacial stage, and 

 very likely some other extinct animals did, so that an argument from 

 association with extinct animals comes to have force only when the 

 relics of man are associated with a large number of extinct animals 

 which carry evidences, or at least the presumption, of having died out 

 before the last glacial stage. In the American caves there is little 

 or nothing in the depth or method of burial to imply great age. 



When the weakness of the cave evidence is joined to that of the 

 gravels and other loose deposits, and to the absence of authentic evi- 

 dence from the glacial tills and the interglacial deposits whence the 

 higher order of evidence is chiefly to be derived, presumption seems 

 to lean to the negative side of the question, and an attitude of sus- 

 pended judgment seems to be required. Proof of the negative prop- 

 osition that man was not in America during the glacial period is 

 not to be expected. His absence may in time come to be assumed, 

 if good evidence of his presence shall not be forthcoming after due 

 investigation under the more critical methods which the case requires 

 and is sure to receive. 



In Europe. — The question of man's presence in Europe during 

 the glacial period is altogether independent of the American problem. 

 The balance of evidence is wholly in favor of the eastern continent 

 as the place of man's origin, and hence the dates of his migration to 

 America, and of his appearance in Europe, respectively, are as inde- 

 pendent as are the respective dates at which the Aryans entered the 

 two regions. There is little doubt that the European data might 

 well be subjected to more severe criteria, both archa?ologic and geologic, 

 and that some at least of the data from the gravels and other loose 

 formations would be found to have but little value. There are, how- 

 ever, some important differences between the European and the Ameri- 

 can data. The European are greatly superior in the mass of mate- 

 rial gathered directly by geologists and archaeologists, under condi- 



