63 



as the transverse power of the respective 

 barks to the force exerted by the growth ot 

 the tree. This force it will be difficult to 

 ascertain ; but it cannot be thought irra- 

 tional to suppose it, under similar circum- 

 stances^ nearly the same. This seems to 

 be supported 'by what follows. 



The relative powers of the different barks 

 can be ascertained pretty accurately, when 

 it will be found that the trees most given to 

 canker, and those which continue longest 

 in an apparent healthy state, without bear- 

 ing, have the strongest bark transversely, 

 and that those which have the weakest bark 

 transversely, are the greatest bearers, and 

 least given to canker. 



This both accounts for the canker, and 

 * how full-grown fruit trees, especially 



