38 MEMBERS OP PLANTS. 



practice. In closely crowded woods, and particularly 

 in pine forests, the want of free air suffocates many 

 of the lower branches, which die, and are thus in a 

 manner pruned by nature. 



The branches, like leaves, may be opposite, alternate, 

 whorled, irregularly dispersed, descending, drooping, 

 as in the weeping willow, or possess various modes of 

 bending. It is worthy of remark, that the sprays or 

 branchlets of trees are much the same in the same 

 species, a circumstance well described by Gilpin, and 

 of considerable interest to landscape painters. 



SCALES, HAIRS, PRICKLES, AND THORNS. 



THE rind of many plants, instead of a smooth bald 

 surface, is clothed with various species of scales, down, 

 wool, cotton, silk, hair, bristles, prickles, and thorns, 

 about whose use various opinions have been held. 



The scales 1 here meant are entirely different in 

 structure from the leaf- scales and flower-scales for- 

 merly described, not having, like these, the character of 

 leaves, and hence the scale-like appearance in pine 

 shoots are not scales but young leaves. Scales are 

 found abundantly on the leaf-stalks of ferns. The 

 beginner must not confound with these scales the bark 

 scales thrown off by some trees, nor the lichens which 

 often encrust bark. 



Hairs 2 on plants, somewhat similar to those on ani- 

 mals, arise, according to Du Hamel, from small bulbs, 

 either within the rind or the first layer of the inner 



(l) In Latin, Rament<s. (2) In Latin, Piti. 



