steuart's planter's guide. 



269 



Instead of suiFeriug injury by this exposure of the 

 sap-vessels to cold, the trees rather acquired new vi- 

 gour from the operation ; and the particular tree 

 alluded to, was unusually luxuriant the season fol- 

 lowing this flaying, which was performed in winter. 

 Now, to apply Sir Henry's analogy of fiir of ani- 

 mals, w^ould an arctic fox have been benefited by 

 exposure to the winter's cold in like plight ? We 

 also think Sir Henry will find the trees of dry cli- 

 mates have a much thicker coating of dead bark than 

 in cold countries, evidently a consequence of desicca- 

 tion*, and, if Sir Henry must have animal analogy — 

 similar to the desiccation and cracking of the skin of 

 man in arid air. 



* We particularize the oak, cork-tree of arid warm Spain, and 

 much of the timber of New Holland. Owing to the hot parch- 

 ing air in the latter place, the epidermis becomes dried to such a 

 degree, that contracting by the droughty, and bursting by the 

 swelling of the enveloped stem, it peels off like the old skin of a 

 serpent, and is often seen hanging upon the tree in large shreds 

 like tattered garments. In several kinds of trees, we have count- 

 ed regular annual rings of desiccated bark ; in some kinds this ap- 

 peared a growth or deposition, in others, mere parched exuviae. 

 Trees attain some age before the exuvice commence ; the deposit 

 begins the first season, even in sheltered situations. The cork- 

 tree, and the small-leaved elm, shew the greatest annual deposit of 

 dry bark. The former does, and the latter is said to belong to 

 warm arid countries ; both form a better nonconductor of heat 

 than any other dry bark we are acquainted with — infinitely better 

 than the bark exuviae of trees which approach the polar regions. 



