steuart's planter's guide. 



303 



oak and the walnut banish them to inferior soil from 

 greater power of occupancy in good soil, as the pines, 

 in their turn, banish other plants from inferior sands 

 — some to still more sterile location, by the same 

 means of greater powers of occupancy in these sands. 

 One cause considerably affecting the natm*al loca- 

 tion of certain kinds of plants is, that only certain 

 soils are suited to the preservation of certain seeds, 

 throughout the winter or wet season. Thus many 

 plants, different from those which natm*ally occupy 

 the soil, would feel themselves at home, and would 

 beat off intruders, were they once seated. We have 

 had indubitable proof in this country, that Scots 

 fir, gi'own upon good deep loam, and strong till 

 (what our author woidd call the natiu*al soil of the 

 oak), is of much better quality, and more resinous, 

 than fir grown on poor sand (what he woidd call 

 the natm^al soil of the Scots fir), although of more 

 rapid growth on the loam than on the sand ; and the 

 best Scots fir we have ever seen, of equal age and 

 quickness of growth, is gromng upon Carse land 

 (clayey allmdum). 



The reason that Scots fir is of better quality, and 

 more resinous, on good loam and moist till, than on 

 poor siliceous ground, may probably be, that the 

 loam contains more oleaginous matter, and other 



