INTRODUCTION. 127 



ment, however skilfully or judiciously performed, can 

 ever compensate for the loss, or overcome all the 

 injury done. But, on the other hand, however well 

 a tree may be planted and placed under the most 

 favouring conditions for growing, the whole prospects 

 may be, and very frequently are, completely blasted 

 by improper and injudicious thinning. 



Mixed plantations are, at all stages of growth, more 

 difficult to thin, require more constant attention, and 

 are more easily injured for want of it than those 

 composed of only one species of tree. Different 

 species of trees also require different modes of thinning, 

 and even the same species grown under different con- 

 ditions require very different modes of treatment. 



Thinning, like pruning, may be justly enough re- 

 garded as a necessary evil, an antidote for a bane, a 

 cure for a disease or at the most, art doing under an 

 artificial system what nature can usually better accom- 

 plish if left alone without such aid. It is no sufficient 

 objection to thinning merely that it is an artificial 

 operation rather than a natural one, because the whole 

 system of tree-culture, whose ultimate object is the 

 fulfilment of some artificial requirement, is essentially 

 artificial. 



The simplest form of thinning is that of cutting 

 down such growths as interfere with the healthy 

 development, value, and usefulness of the remaining 

 crop, and it is this form of thinning that has probably 

 suggested the term " weeding." There is certainly 

 more reason for the use of the term " weeding " than 

 at first appears ; for according to Mr Stephens's ' Book 

 of the Farm,' a weed is defined as signifying a plant 

 growing where it should not grow, or where, for the 

 time being, it is not desired it should grow. The 



