318 



and lost to the crops. A bub-stratum of cemented gravel, retentive of 

 water, is common to many, if not all tlie prairies, and to this circum- 

 stance may, no doubt, in a gieat measure, be ascribed their accumula- 

 tion of rich loam, and consequent fertility. 



Much curious inquiry has been excited on the question of the causes 

 which produced the peculiar, varied and open character of so large a 

 portion of our Peninsula. After the view which we have just taken of 

 our diluviums, it may seem less a matter of surprise, that portions of 

 the State should be adapted to the production of a dense growth of 

 hard timber, and others only to the several species of oaks, or to hick- 

 ory, according to the continually varying conditions of the soil, and its 

 sub-strata. The existing analogies of the vegetable world, which ex- 

 hibit similar results elsewhere, might lead us to infer these changes, 

 and we may, without doubt, attribute to the peculiar characteristics of 

 our diluvial envelop, and its varying conditions, the accompanying pe- 

 culiarities in the features of the country, and the growth and character 

 of its timber. 



How far the impervious character of the "hard pan," which so 

 generally, if not universally, forms the sub stratum to the prairies and 

 plains, may account for the destitution or sparse growth of large trees, 

 we are not altogether prepared to decide, and therefore, avoid for 

 the present, considerations, which at best, may be considered somewhat 

 theoretical. Nor will we assume 1)0 decide, with confidence, upon the 

 extent of the effects produced by the ravages of the annual fires which 

 formerly swept over these tracts. It is but reasonable to conclude that 

 all these, and perhaps other concomitant causes, have operated together 

 in producing the results we witness, while, according to peculiar circum- 

 stances, one of these several causes, may have operated more or less 

 powerfully than others. 



ANCIENT ALLUVION, 



As the consideration of that immense mass of materials, to which 

 has been applied the name of diluviums, or erratic block group, was 

 necessary, in order to a correct appreciation of those lesser deposits, now 

 to be considered, (which are associated with, and in fact, compose a 

 part of the former,) that important group claimed our first attention. 

 We come now to the consideration of a class of deposits which may be 

 called alluvial. 



