FIG. 49. Section of portion of the stem of a young 

 apple-tree, showing the effect of pruning and not 

 protecting the cut surface. The dark portion is 

 diseased owing to a parasitic fungus having entered 

 the tissues through the unprotected wound. The 

 tree died due to the spread of the fungus in its tissues 

 some years after it was attacked. Fig. reduced. 



