28 KANSAS CIl V REVIEW OF SCIENCE. 
To comprehend this clearly, we must imagine a rock-bound canyon of vari- 
able width, cut through the carboniferous strata between the bluffs on either side 
of the river, to a depth of five hundred feet or more, below the present bed, at 
the bottom of which the river was dashed in wild confusion ; then we must con- 
ceive of vast rivers of ice, creeping down from the north, laden with great streams 
of stones and sand, to be emptied into the canyon, in quantities sufificient to fill 
and completely dam it up in many places ; but, at the same time, it must be borne 
in mind that at the interval the glaciers reached the Missouri River the volume of 
water was greatly diminished in it, in consequence of the congelation of the 
snow and rainfall over all the country north of the 40° of north latitude. 
The Glacial period is distinguished by its wide-spread distribution of eratic 
rocks over all of the country north of the 40° of north latitude. It has but few 
fossil remains, and those, mostly of life which preceded it. 
The Champlain epoch next followed, and was, in every way, in strong con- 
trast with the Glacial period. 
Most of the country along the Missouri River, which, during the Glacial 
time, had been elevated above the present level, in the Champlain era was sunk 
below it. Instead of intense cold, the climate was warmer than we now enjoy. 
Instead of vast fields of moving ice, still lakes prevailed along the Missouri 
River, co extensive with the Loess formation now bordering it. Instead of an 
arctic waste, life teemed in the water and upon the land. The lakes were filled 
with fish, and the land abounded with animals. Among the animals the elephant 
and the mastodon browsed among the hills and valleys. The horse, much larger 
than the living species the ox, and the bison grazed on the plains. A gigantic 
beaver, and animals of the sloth tribe, much larger than the moderns, prevailed. 
Among the carnivores there were bears, lions, and a species of raccoon ; and last, 
though not least, we have a glimpse of man playing a part for supremacy in this 
remote era. The remains of several of these animals have been found imbedded 
in the Loess deposits about Kansas City. This era is distinguished for its great 
deposits of brick clay, or Loess, its terrace formations, its gigantic mammals 
which have become extinct, and for the great number of its mollusks, which are 
identical with living species. Next, the era of mind was ushered in, and is still 
slowly fulfilling its promise of a higher desliny. 
CORRESPONDENCE. 
SCIENCE LETTER FROM PARIS. 
Paris, April 10, 1883. 
Dr. Delaunay publishes a very remarkable work on " Medicine as Practised 
by Animals." There is less sickness among the latter than with man, and much 
of the difference may be attributed to the instinct of animals in prescribing for them- 
