326 L. Lesquereux on the Origin and Formation of Prairies. 
passing to prairies." The only fact, to my knowledge, whic 
could be mentioned as sustaining the assertion of Prof. Winchell 
The clayey subsoil mixed with the black mould forms a com 
pound which combines density of certain parts with clr! 
of others, and contains a great proportion of nutritive sme CF 
If the clay of the subsoil is not too thick to be impermeab sae 
water, and thus retain it around the roots, this prepared or a vid 
ficial ground is indeed very appropriate to the growth o ad at 
ut has any one ever seen oak or hickory, or any other kin a 
ees, grow on the prairies from a handfull, say even from 
® Species of trees like the magnolia grow over the southern peat bogs for - 
Same reason that tamaracks grow in the peat bogs of the north. 
e Vegetale, pp. 1206-1212. eo 
