Pev)<oi}al and Sclent i-fif Xt-vx. 195 
The Baron de Geer, of Stockholm, gave aa interesting and valuable 
laccount of the Quaternary changes of level in Sweden which elicited 
several remarks on their resemblance to contemporaneous changes 
in this country. He instanced several extensive oscillations be- 
fore, during or after the Gracia) era, during some of which great 
part of the country was below the sea and other parts reduced 
to the form of islands. Prof. Krassnof discussed the "black earth" of 
southern Russia, and its resemblance to the soils of the American 
prairies. This elicited a discussion on the complexity of the problem of 
these soils, and the morning session closed with a short paper read in 
French by Prof. Stefanescu, of the University of Bucharest, on the 
occurrence of Dinotherium in Roumauia. 
Pres. T. C. Chamberlin in the afternoon summarized the standing of sev- 
eral of the theories which have been suggested to explain the occurrence 
of the Ice age. After stating that the hypothesis of CroU now fails to 
account for the phenomena, at least on this continent, he hastily sketched 
the theory of elevation as the cause of the cold, and offered as in his 
view most probable a change of the axis of the earth's rotation. In the 
discussion that followed some opposition was developed and it was 
apparent that the geologists present were far from agreement on the 
subject, a result that might have been anticipated. 
The society was divided into two sections in order to render the com- 
pletion of the program possible. Papers on the drift and kindred 
subjects were read in one room and the rest in another. Mr. R. D 
Salisbury mentioned the occurrence of the preglacial Orange sand 
of the Mississippi in Illinois and Indiana and at levels considerably above 
the present river, indicating the attitude of the country at that time. 
He also stated the occurrence of an older drift outside the so-called 
terminal moraine in New .Jersey and referable to the earliest drift of 
which we have any knowledge. Mr. S. suggested further that though 
we are accustomed to speak of two glacial eras, yet there may have been 
three, the earliest of which is represented by the deposits which 
he described, the second by the silt layer and the third by the mo- 
raine. 
Petrographical papers were presented by Mr..!. F. Kemp and Mr. O. A. 
DerbJ^ Mr. R. T. Hill contributed one on the geology of Texas and New- 
Mexico and Mr. Winslow another on the condition of deposition of the 
Missouri Coal Measures. 
Prof. Safford exhibited some interesting specimens consisting of the 
bones of a Megalonyx, from Big Bone lick, Ky. These he considered 
to be the remainder of the skeleton of the animal discovered by Leidy 
in his "Contributions." Like those some of them showed the remains of 
cartilage indicating no excessively ancient date. 
In a short address Prof. E. W. Claypole related the discovery of a deep 
preglacial channel previously unsuspected. It is about five miles from 
Akron, O. The auger went down nearly 4{)() feet before the rock was 
reached showing that at this point the old river bed was cut down to 
the level of lake Erie tliougli 40 miles distant. 
