ENEMIES OF CONIFEROUS TREES 273 



actual disease, being merely epiphytal, yet, when 

 mosses and lichens abound, the health of the tree 

 is injured and the affected branches die oft gradu- 

 ally. In some cases that have been brought to 

 my notice, large numbers of trees have fallen a 

 prey to their attacks. To combat them 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 ? On what species, and 

 under what conditions, do they grow most ? These 

 are questions more readily asked than answ^ered. 

 Both epiph3rtes 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 Uchen is plentifully distributed on 

 many hard-w^ooded trees. Probably, the fact that 

 neither mosses nor lichens penetrate into the tissue 

 of the wood, wiU explain why they commit less 

 damage than is generally supposed. 



''Beard Mosses" [Usnea barbafa), so commonly 

 distributed, are usually found where the atmo- 

 sphere is constantly damp. In order to get rid 

 of moss and lichen on trees, fresh powdered lime 

 should be sprinkled on these during damp weather ; 

 or, better still, scrape off as much of the moss and 

 lichen as possible, and then thoroughly scrub the 

 bark with limewash made from fresh lime, so thin 

 as to give a slightly white appearance when dry. 

 Sulphate of iron in the proportion of one pound 

 weight to a gallon of water will also destroy these 



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