no TREE WOUNDS AND DISEASES 



abound, the health of the tree is injured and 

 the affected branches die off gradually. In 

 some cases that have been brought to our 

 notice, large numbers of trees have fallen a prey 

 to their attacks. To combat these attacks, 

 drainage and the admission of light and air 

 should be attended to. 



How far does the growth of mosses and 

 lichens affect the health of trees ? and on what 

 species, and under what conditions, do they 

 grow most ? are questions that are more readily 

 asked than answered. Both parasites prevail 

 more on the west than the east coast, owing 

 no doubt to the greater rainfall, and several 

 species seem to grow alike either on stones 

 or trees. The larch suffers most in the south 

 and south-west of England, and in Devon and 

 some of the adjoining counties the common 

 grey lichen is plentifully distributed on many 

 hard-wooded trees. Probably the fact that 

 neither the moss nor the lichen penetrates 

 deeply, if at all, into the tissue of the wood, 

 will explain why they commit less damage 

 than is generally supposed. 



The beard mosses (Usnea barbata]^ so 



