[Upham. 
1890.] 4<)5 
be identical, and if this period coincides with the glacial period, as 
it appears to do, then we may fairly assume that the climatal con- 
ditions immediately to the south of the glacial sheet were not those 
of extreme cold. This evidence has nothing like the sure founda- 
tion, as that obtained by the lack of glaciers in the mountains of 
North Carolina, but as far as it goes it confirms the results of those 
observations. 
It is not my purpose, however, in the present writing to con- 
sider the perplexing question as to the cause of glacial climate. 
I desire only to call attention to the extent to which our glacial 
streams appear to have advanced, by what we may term forced 
marches, far to the south of the line of perpetual snow. Although 
the value of the evidence above noted cannot be determined until the 
matter has been more carefully brought together and abundantly 
discussed, the facts seem to me to militate against any hypothesis 
which seeks to account for the glacial period on the supposition 
that the climate in the glaciated regions was cooler than at present. 
In the subsequent discussion, Mr. Upham spoke of the very ex- 
ceptional character of the climate of the glacial period. He be- 
lieves, with Nordenskiold and Wallace, that there was no wide- 
spread glaciation at any time during very long preceding geologic 
eras. The ice-brought blocks in Miocene deposits south of the 
Alps, and other local glacial formations of Tertiary and Mesozoic 
age are so infrequent that they seem to be best explained by ref- 
erence to alpine glaciers at times of great uplift of neighboring 
mountains. But more widely distributed evidences of glaciation 
occur in the Carboniferous and Permian series, boulder-bearing 
deposits of so remote age, closely like the Quaternary till, and 
also striation of the underlying rock, being found in Natal near 
latitude 30° S., and in India only 20° N. of the equator. Appar- 
ently contemporaneous glacial deposits are also known in south- 
eastern Australia, in Great Britain, and elsewhere. Croll has 
shown that the coal measures were laid down under cool temperate 
climates, attended by frequent oscillations of the land, like those 
of the Quaternary period ; and it is very probable that many Car- 
boniferous and Permian conglomerates were formed by ice-sheets. 
Looking for causes of glaciation which could have acted effi- 
ciently at the close of Palaeozoic time and again after the Tertiary 
era, upon the threshold of the present, Mr. Upham thinks that 
30 MAT, 1890. 
PROCEEDINGS B. S. N. H. 
VOL. XXIV 
