THE planter's GUIDE. 



71 



time is undisturbed by the external impediment of ^Ymd, 

 Here nature has no need, as in the case of exposures, to 

 generate provisions necessary to mitigate the effect of 

 evaporation, as has been above observed, or to endue 

 each individual tree with distinct and appropriate means 

 of defence against the elements. In this situation the 

 branches, and in like manner the roots, are much less 

 extensive and numerous than in the former instance, and 

 the bark of a thinner and finer quality — all plainly indi- 

 cating, that the trees so situated do not require the same 

 external protection. It is like the genial warmth of the 

 seed-bed or the nursery, but where there is freedom for 

 the roots to expand without interruption, and for the 

 leaves to prepare the sap without being vexed by the 

 winds. In fact, so extraordinary is the difference between 

 trees of the same species, placed in the one situation and 

 in the other, that there is no visible point of resemblance 

 between them, excepting the leaves. We may, however, 

 perceive that, as soon as the tops gain the summit of the 

 wood, their branches are shortened towards that quarter, 

 and both branches and spray are more thickly, though 

 less vigorously, thrown out, in order to supply a defence 

 against the storm. Further, we find that the outside 

 rows, partaking in some measm^e of the situation of trees 

 in exposures, obtain, in a proportional degree, the pro- 

 visions adapted to such a situation, and by consequence, 

 a corresponding confirmation and external character. 



It is a very curious fact, which has been verified by 

 experiment, and is worthy the attention of the scientific 

 planter, that these several properties or provisions, though 

 once determinately acquired, are not fixed or permanent 

 in trees. The vigilance of nature, if I may so speak, in 

 adapting them to every vicissitude of external circum- 

 stances, is so conspicuous as to dispose them gradually to 



