Upham.] 
450 
[Jan. 1. 
only a graduate of the college, but he was educated as a lawyer, 
passed several years of study in Europe, and is a man of the high- 
est personal character, accustomed to weigh evidence, and not 
likely to be deceived. 
I remain, etc., 
Charles F. Adams. 
Adams Building , 23 Court Street. 
The following abstracts of the remarks made by those who took 
part in the discussion of the 44 Climatic Conditions of the Glacial 
Period ” have been prepared by the speakers. 
THE GROWTH, CULMINATION, AND DEPARTURE OF 
THE QUATERNARY ICE-SHEETS. 
BY WARREN UPHAM. 
As the character of a man is discerned by his life and work, so 
we may learn what were the climatic conditions of the glacial pe- 
riod by the study of their results in the formation of ice-sheets 
whose farthest extent and stages of recession are known by the 
limits of glacial striation and deposits of till or boulder clay and 
by the course of terminal moraines. In this inquiry we may prof- 
itably consider the climatic changes producing glaciation in their 
manifestation successively by the growth, culmination, and de- 
parture of the ice-sheets. The most interesting and difficult cli- 
matic problem presented in all the geologic record is that of its 
latest period, immediately preceding the present, to discover the 
causes of the accumulation of its vast sheets of land-ice. So wide 
and careful investigations have been bestowed on the glacial drift 
that we are enabled to outline definitely the boundaries of the ice- 
sheets both at their time of maximum extent and during pauses or 
times of re-advance interrupting the general retreat. Further- 
more, evidence is found both in America and Europe showing, as 
many geologists believe, that there were at least two principal 
epochs of glaciation and between them a very long interglacial 
epoch when the ice was restricted as now to alpine glaciers and 
polar regions. 
The fossil floras of Greenland and Spitzbergen indicate that 
