THE PLANTER S GUIDE. 



83 



be in the proportion of their deficiency. It is manifest, 

 on any other supposition, that we must believe Nature to 

 act here in contradiction to herself, which is impossible ; 

 although her most obvious processes are many times 

 misunderstood by the blindness of man. 



Such is the short history of my own progress, and of 

 that plain and practical system on which I have con- 

 sequently acted. It is unencumbered with complex 

 notions or technical details. Its soundness has been 

 proved by the experience of many years. The principle 

 has been occasionally relaxed, or stretched to the utmost, 

 as circumstances of comparative shelter or exposure 

 required ; and the uniform success attending the pra.ctice 

 leaves no room to doubt that a similar system, if adopted 

 by others, will secure similar results. 



As it is of the utmost importance to the young planter 

 toapprehend as much of vegetable physiology as imme- 

 diately relates to this subject, so that he may be enabled 

 to appreciate the above properties or prerequisites, I beg 

 leave to call his attention to a few observations which I 

 shall make upon each of them. For this purpose let us 

 consider the relative nature and importance of these 

 prerequisites, in reference to the art and to one another, 

 and draw such conclusions as may be useful in throwing 

 light upon the principle just now laid down. 



First. — As to superior thickness and induration of 

 bark. The bark of trees is accounted by phytologists as 

 among the composite organs. It consists, first, of the 

 epidermis, or external cuticle or integument of the plant ; 

 secondly, of the cellular tissue or parenchyma — ^that is, the 

 soft pulpy substance, situated immediately undei* the 

 epidermis, and constituting a sort of secondary integu- 

 ment ; and thirdly, of a number of thin cortical and con- 

 centric layers, composing the mass of the bark ; of which 



