^Fan and the (rlarkd Period. 195 
not call foi" more than one ice period, sulxlivided into epochs l)y 
successive terminal moraines. There are forest l)eds and claj's 
between sheets of till, but nothing of much magnitude — nothing 
more than could accumulate in the time elapsing between the for- 
mation of the moraines. On the sea shore we have clearl}', first, 
an earl}' pre-glacial Quaternar}' deposit with numerous fossils, 
such as the quahog and oyster; second, the Champlain marine 
beds, both littoral and pelagic, of an arctic character, and hence, 
presumabh' glacial; and, third, sands and cla3's with modei*n 
shells and other organisms in them. Many of the so-called 
Champlain deposits belong to this later perioil. The possil)ilit3' 
of a dual Ice-age has alwa^'s been borne in mind in my glacial 
studies, but I have not yet seen any wide-spread phenomena de- 
manding such an interpretation of nature. 
WlI.\T WAS THE OrI(;IX OF PoST-(jl LACIAL MaN? 
Prof. Putnam regrets that, much as he would like to express 
his views on the subject of palaeolithic man, his duties make it 
impossible at present. He saj's: "Nothing which I have yet 
read on the subject has shaken my faith, as these articles have 
onlj- been partial treatments of the subject ; while all admit that 
man must have been on the North American continent at least as 
early as the close of the Glacial period. 1 simply ask. Where 
did he come from at that time?" 
AdDII'ION.VI, KvUtKNCE HEAR1N(} UPON TriE GlACI.M, HlSTOKV oP 
THE Upper Ohio Vali.ev. 
By Prof. G. F. Wright, Oberlin. 
Several of the most important ([uestions relating to present dis- 
cussions concerning the unity of the glacial period in North 
America have much light shed upon them by the gravel deposits 
of the upper Ohio valley. As is well known, these deposits are 
mainly found at two rather definite levels. The lower terraces 
rise directly from the river l)ed to a hight which rarely exceeds 
120 feet; even this hight is attained only where the northern 
tributaries which come in from the glaciated region, were sup- 
plied, during the close of the glacial period, l)oth with super- 
abundant floods of water and with superabundant glacial ili'hrlst. 
