10 REPORT ON THE BOTANY OF 
neath the sod, suffered no damage. But as these fires were 
annually kindled, how did it happen that here and there all 
over the broad prairies clusters of trees withstood their de- 
structive influence, and lived and flourished? The reason of 
the deficiency of trees on the prairies has been held by some 
to be the absence of the nutriment in the soil which they 
required, or the fineness of the soil, which was supposed to be 
unfavorable to the growth of timber trees. This latter view, taken 
in connection with the fact that the knolls on which the clumps of 
trees are generally found are composed of more porous ma- 
terial, as sand or gravel, seemed to receive confirmation. But 
the fact that all kinds of trees do grow well when planted and 
protected in prairie soil, upsets both these theories without fur- 
ther refutation. The soil is not too finely divided; it does not 
lack the necessary constituents. Not taking into consideration 
how a country may have been deprived of a forest—whether 
by the ravages of insects, a succession of unfavorable seasons, 
or by a conflagration alone, or connected with one or all of 
the foregoing causes, or by any other cause—when once de- 
prived of a forest, annual fires would likely prevent its restora- 
tion while they were continued. If the fires were purposely 
kindled, and at a certain time, so that the villages could be 
protected against their ravages, the inhabitants would do it by 
clearing away the dead grass from the vicinity of their dwell- 
ings. In fact the grass would perish to the roots around their 
villages from being trampled upon and burnt out by the fires 
in and about their habitations. It is not beyond supposition 
that the aborigines themselves, for various reasons, might 
scatter the seeds of trees intentionally or accidentally, from the 
mast with which they must have provided themselves for winter 
consumption. They would occupy the knolls, if such there 
were, for their villages. The aboriginal well knew where the 
beds of gravel were, as is proved by the use he invariably 
made of them as repositories of his dead. Throughout West- 
ern and Southern Ohio scarcely a terrace gravel-bed has been 
dug out and removed for road-making, but has been found to 
have been used as a place of interment for his dead. 
36 
