82 
ORIGIN OF LIFE IN AMERICA 
Dr. Tcherski’s * expedition to the New Siberian Islands were 
published by the Academy of Sciences in St. Petersburg ; and 
it is of interest to note that he arrived at conclusions similar 
to those of Sir Henry Howorth. He contended that the causes 
which produced glaciation in Europe acted in quite a different 
manner on the conditions of life in northern Siberia, where 
the climate remained as a direct continuation of that pre¬ 
vailing in Tertiary times, so that this country had a higher 
temperature during the Pleistocene Period than obtains at 
present. 
He looks upon Siberia as a country in which the processes 
of general refrigeration of the northern hemisphere and the 
deterioration of the conditions of existence for plant, and 
animal life during the post-Tertiary Period took a regular 
and steady course. 
Baron von Toll concurs with Tcherski and other writers in 
their opinion that the large mammals whose carcases and 
skeletons are now unearthed in the extreme north of Siberia 
really lived there, but he urges that they did not arrive there 
until after the Glacial Epoch. Underground ice, as in some 
parts of Alaska, is extensively met with in northern Siberia 
and in the New Siberian Islands. Its occurrence, according 
to Baron von Toll, is due partly to a recent origin in crevices 
and lateral infiltration, partly to a former glaciation of Siberia, 
the ice having been preserved as “ relict ice ” from the Glacial 
Epoch. Being a follower of those who connect that period 
with a universal lowering of temperature, his contention is 
that northern Siberia enjoyed a milder climate in post-Glacial 
times, and that the mammoth, horse, rhinoceros and other 
mammals were thereby induced to visit the shores of the Arctic 
Ocean and the New Siberian Islands, which, according to 
Baron von Toll,f were then connected with Siberia and arctic 
America. 
The mammoth and many other animals, as I have indi¬ 
cated, invaded America from Asia. Consequently, if we can 
determine whether a land connection existed between the 
two continents, how long it lasted, and what species made use 
of it in their travels, some valuable data may be obtained as a 
* Tcherski, J. D., “Das Janaland,” p. 469. 
t Toll, Eduard von, “ Die fossilen Eislager,” pp. SO—So. 
