Fo ee ee ee ee ee ee 
L, Lesquereuz on the Origin and Formation of Prairies. 23 
Arr. I1l—On the Origin and Formation of Prairies; by 
Leo LESQUEREUX. 
{Concluded from vol, xxxix, p. 327.] 
E now come to the examination of the new theory of Prof. 
Winchell.’ A clear abstract is given by the author himself in 
the following words: 
1. The soil of the prairies is of lacustrine formation, as proved 
by its physical characters, and by the necessary effect of 
logical changes of level which are generally admitted to have 
taken place 
2, Lacustrine sediments enclose but few livin germs. ' 
8. Diluvial es red “on the contrary, are found everywhere re- 
plete with living ger 
4. The living area of the diluvial deposits were buried dur- 
in g the prime 
5. In riot? as the diluvial surface became exposed, the 
flora of the _ glacial epoch was reproduced. 
vegetation which finally appeared on the drained la- 
custrine asbd was extra-limital, and was more mer to be herba- 
ceous than ar 
prairies, but nae that of the high rolling prairies, and as, in re- 
marking on the extent of the ancient lakes, he says that its arms 
reached into Iowa, we may admit that the high rolling prairies 
of this State are considered by him as resulting from the same 
lacustrine action. We might go farther west, and follow the same 
formation over a surface continually rising to an elevation of 
feet. But it is not necessary for our present argument. 
In Iowa the knolls of the high prairies are 1,500 feet above the 
Ocean, and as Lake Michigan is only 600 feet above the sea, its 
waters, to reach the high prairies of Iowa, should have been 900 
feet higher than they now are. How would this agree with the 
actual configuration of our country? Moreover, as the level 
: This Journal, Nore 
* Prof. ie Goth, Rages af lowe, p 19; for this and some of the follow- 
Those for Ohio are taken n from official surveys for canals. 
