TIME DIVISIONS OF THE ICE AGE. 401 
Rome, New York, to the Mohawk and Hudson Rivers. In 
the meantime a gradual re-elevation of the Rome outlet 
from the Champlain subsidence lifted the surface of Lake 
Troquois in its western part from near the present lake level 
at Toronto to a height there of about 200 feet, finally 
holding this height many years, with the formation of the 
well developed Iroquois beach. The glacial and lacustrine 
geology of the vicinity of Toronto is therefore perhaps of 
greater interest than of any other locality in America; but 
its remarkable features of alternating glacial and _ inter- 
glacial formations seem to me wholly referable to the 
Champlain epoch of wavering departure of the ice-sheet. 
STAGES OF PROGRESS OF PRIMITIVE MAN CORRELATED WITH 
THE STAGES OF THE IcE AGE. 
To many members of the Victoria Institute, the history of 
the Ice age derives its greatest interest from its relation to 
the earliest traces of man’s existence. We are able now, as 
I believe, to discern a reliable parallelism of the stages of 
progress of Paleolithic men, using chipped stone implements, 
with the stages of the Glacial period which have been here 
reviewed. ‘This correlation has come from my examination 
of the Somme river valley and its famous implement- 
bearing and fossiliferous sand and gravel beds, during the 
summer of 1897. There, between fifty and thirty years 
earlier, the great geologic antiquity of man had been first 
fully determined by Boucher de Perthes, Rigollot, Falconer 
and Prestwich, Evans, Lyell, Lubbock, Tylor, Gaudry, 
Andrews, and other archeologists and geologists. 
The men of the Somme gravel deposits belonged, if I 
rightly interpret the geologic record, to the early part of the 
Glacial period, previous to its culmination; the inhabitants 
of the caverns of Dordogne, in south-western France, 
possessing greater skill in the manufacture of flint imple- 
ments and adding others of bone and horn, hunting herds of 
wild horses and reindeer, seem correlative with the 
maximum stage of glaciation; and later these people 
spread northward, following the retreating ice-sheet to the 
boundary of its Mecklenburgian stage. 
De Mortillet and Cartailhac, as archeologists, divide the 
Paleolithic period of France into four epochs or stages, 
succeeding one another as follows: 1, Acheulian, named 
from St. Acheul, a suburb of Amiens in the Somme valley 
2D 
