MANAGEMENT OF DECAYING TREES 7 



Scotch pine is attacked in a wholesale manner 

 by the pine beetle, and whole beech woods 

 have been destroyed by a species of coccus 

 which, of late years, has been alarmingly on 

 the increase in this country. 



Every tree is perhaps liable to some acci- 

 dent, disease, or malady, and the object of the 

 present work is to direct attention to some 

 of the most serious, and, if possible, suggest 

 suitable remedies. 



Though as far as possible popular names 

 are used in describing the various parts of a 

 tree, yet, to the uninitiated, the meaning of 

 such terms as pith, cambium, and medullary 

 rays may not be understood, and to aid the 

 reader the following notes and diagram of the 

 cross-section of a tree stem are added. On 

 examining a piece of timber it will be found to 

 consist of (i) the bark or cortex, (2) cambium, 

 (3) sapwood or alburnum, (4) heartwood, and 

 (5) the central pith ; in addition to which there 

 are the annual rings and medullary rays. 



The pith, or central part of the stem, which 

 is composed of cellular tissue, is relatively 

 large in young plants, but does not increase 



