516 



ON USEFUL AND 



BOOK I. 



and as this tree will generally pay better than more valuable 

 kinds that would not thrive, or would grow too quick there; it 

 follows, that, in the formation of useful plantations, one great 

 object should be, to accommodate the trees to these circum- 

 stances. Now, as the properties of soils and situations are va- 

 rious, this naturally leads to a corresponding variation of the 

 species of tree also; and this variation at once produces ornament 

 and utility. Now, in natural forests, such an arrangement ac- 

 tually takes place. Thus in one part, Ave find the oak as the prin- 

 cipal tree ; the hazel the principal undergrowth; the cowslip the 

 principal plant; the poa nemoralis the principal grass; and the 

 hypnum the principal moss. Farther on, a few beeches mingle 

 with the oaks; proceeding onward, beech becomes the principal 

 tree. The undergrowths changing in the same way, we there 

 find the thorn, the violet, the poa trivialis, and the bryum. The 

 ground becomes moist, and the birch gradually appears; the 

 moisture increases — and, as the birch retires, the alder succeeds 

 — each with appropriate undergrowths, or ever-varying glades of 

 pasture*. The arrangement goes on thus throughout the whole 

 forest ; and if the soil were examined, it would be found to 

 vary correspondently with the trees. Where the oak abounds, 

 it will be found deep and good ; dry where the beech prospers, 

 and moist where the alder prevails. An adequate idea is sel- 

 dom formed of the effects and advantages that might be pro- 

 duced by adopting this mode of arranging vegetables in arti- 



•* See Gilpin's Forest Scenery. — Walks in a Forest, &c. 



