A. Winchell on the Prairies of the Mississippi Valley. 335 
which they saw the proofs had nothing to do with the formation 
| of the prairie soil.* sp 
The aqueous origin of the soil of the northwestern prairies 
a was intimated by George Jones in 1836,’ who compares the 
prairies and barrens of Illinois to the marshes, dykes and sand 
flats of Holland. Lesquereux, in 1856," ascribed the general 
_ formation of prairies to water, and in 1861” reaffirmed his posi- 
tion in reference to the prairies of the Mississippi valley. Prof. 
J. D. Whitney has distinctly asserted a lacustrine origin for the 
prairies of the northwest,” and Dr. J. 8. Newberry ” has recog- 
nized the evidences of a former efflux of the lake waters over 
the Kankakee ridge in northern Illinois. The indications, in- 
deed, seem to be sufficiently patent to induce the genere 
of living geologists to the doctrine of the lacustrine origin of the 
soil of the prairies. a 
2. Lacustrine sediments inclose but few living germs. 
_ OF the seeds which find their way yo a body of fresh water, 
_ * This Journal, xxiv, 187.  Ib., xxvi, 98. < = 
2. Bete or the esse ete he was the first to assert the cota 
: the Alabama prairies and to maintain it—even in opposition to views eg by 
yume 
i his Jou XXxili, p. 225. 
‘es “4 Bullet. on Nat. Sti Neuchatel. 11 See 2d Geol. Rep. Ark. 
4, Hall’s Geol. of Iowa, i, p.25. 
a Proce. Bost, Soc. Nat. "Hist, vol. ix, May, 1862. 
* 
