52 Editorial Comment. 
a metaphysician. Geologists may also take a suggestion from 
it. The human element in our science goes far to keep it in 
relation with the current thinking of the world. That portion 
of geological time during which man has existed upon the 
earth is insignificant when comj^ared with the whole record, 
yet in that relatively brief interval the chief interest centers. 
The bare question, how long ago man first appeared, is not 
the onl}'^ point of interest. Was the first man white or black, 
ape-like or human? Is the race a unit or of multiple origin? 
What continent witnessed the first human birth? These and 
many similar questions vibrate about the cradle of the race, and 
some of them are of greater importance than the mere lapse of 
years since the introduction of man. 
The perennial interest in the antiquity of man constantly 
brings this topic to the front in spite of the frowns of those 
geologists who deprecate any attempt to express geological 
time in years. And the discussion justifies itself, if not by set- 
tling the main question, at least by throwing much light upon 
other incidental questions. When it was found that man was 
contemporary with many species of extinct mammalia, the 
question how long ago these species became extinct assumes 
new importance. As a consequence of the impulse thus given 
we know more about the time of disappearance of the Quater- 
nary mammals than we should otherwise have known. They 
are found to come to a later period than was at first supposed. 
In like manner the association of human remains with the 
Glacial period has caused the remoteness of that period to be 
sharply called into question, with the same result of bringing it 
nearer to our own times. Mr. James CroU at first put it in the 
phase of great eccentricity of the earth's orbit which occurred 
980,000 — 720,000 years ago. In other words he thought the 
Glacial period began about a million years ago and lasted a 
quarter of a million years. Later he placed it in the eccentric- 
ity phase 240,000 — So,ooo years ago. 
These dates are astronomical and have not been generally 
accepted by geologists. Still they served to give a measure of 
definiteness to the common impression that the Glacial period 
was very remote. In the light of new evidence these great 
figfures have shrunken to modest dimensions. In the Auo^ust 
