40 TRANSACTIONS OF THE ILLINOIS 



roots. A tree thus situated, whether it strikes its roots deep into a poison- 

 ous subsoil or, horizontally into an open topsoil, is in danger of coming 

 to grief. 



But it is both of these conditions we must cure to have success in 

 tree growing. Pasturage and cultivation do much in admitting the sun's 

 rays and promoting evaporation ; in giving a free course to water and 

 securing a mere rapid drainage. The surface soil settles, too, as it is cul- 

 tivated, several inches and becomes compact, so that wheat grows on land 

 where it would formerly not endure the winter; and, in like manner, 

 trees grow, even spontaneously, on lands once entirely unsuited to their 

 existence. These are the improved conditions that come without special 

 preparation. 



Again, a good deal can be done artificially. Surface drainage can be 

 promoted rapidly by ridging land, as our worthy president does in his 

 orchards, and, more slowly but more satisfactorily, by ploughing fields in 

 one's land and always throwing the furrows to the center, which, before 

 many years, will clear even a level field of surplus surface-water. 



But it will be found, probably, that the amount of land of this char- 

 acter, that any one will desire to plant, will be small. The artificial forests 

 that furnish the timber of the future can be grown more economically in 

 lands that, from their broken surface or for other reasons, are not adapted 

 to field culture. The plantations that the farmer on the wet prairies will 

 desire to make are of belts and clumps, to break the force of the winds 

 and storms, to husband moisture, and incidentally furnish timber for fuel 

 and farm uses where coal and sawed lumber cannot be had at reasonable 

 rates. 



An interesting point, which I touched upon in my report last year, is 

 the probable natural order, if there be any, of succession in plant growth 

 on our Illinois lands. Mr. Lesquereux believes that when the water 

 becomes as shallow as three or four feet, Mosses, Confervae and Charas 

 begin to appear. At a depth of one foot Sedges begin to appear, and 

 then coarse grasses. Then apparently the order is more uncertain, as 

 accidental causes bring in the seeds of differing plants that will succeed 

 more or less in establishing themselves. This brings up some curious 

 questions. Why is the Persimmon, a tree which grows and thrives on dry 

 land, found standing so often in soil that is at least a part of the year 

 covered by water ? Why does the Willow, of the wild species, seem to 

 affect the streams rather than the pools ? Why does the Black Jack Oak 

 start up in the prairies where no other oak survives? Why does the 

 Mocker-nut Hickory do the same ? We can speculate upon the reasons 

 of these facts, but I find them difficult to positively account for. But we 

 find that for some reason one tree grows by nature, or favoring natural 

 conditions, while another does not ; that one species or variety of tree, 

 when planted, thrives easily, while another can be hardly kept alive by 

 the most skillful treatment. We may assume, perhaps, that the trees that 

 grow readily do so from fitness ; that the Laurel Oak, the Post Oak, the 

 Water Oak, the White Elm and Cottonwood, that we find growing on 

 the borders of our flat Southern Illinois prairies, and in wet cold lands on 



