EEV. M. J. BERKELEY ON VARIOUS FORMS OE CANKER. 27 



tips soon die, and the taint is rapidly communicated to the under- 

 lying tissues : new wood and bark are formed round the patches, 

 which are in consequence sunk more or less deeply ; the sides of 

 the surrounding wood and bark are soon more or less involved in 

 the disease, the hollow becomes ragged and unsightly ; whole 

 branches by degrees perish from the disease being carried round 

 them, the truuk itself is filled with unseemly cavities, and the 

 tree at length dies. Much the same process takes place frequently 

 in the common Laurel, less frequently perhaps in the Laburnum ; 

 and there can be little doubt that the mischief arises rather from 

 a bad condition of the roots than from any deleterious matter 

 being imbibed. I Lave no information to show whether this form 

 of Canker admits of remedy by lifting or not. 



3. A third form of Canker is extremely common, and shows 

 itself in various ways. Either distinct patches of diseased tissue 

 appear on different parts of the tree, or whole branches perish at 

 once, the cuticle in most instances shelling off from the other 

 portion of the bark. This undoubtedly in many cases arises from 

 decay of the buds. Water collects in drops upon the buds and 

 congeals, the vitality of the buds is lowered, disease takes place, 

 and the tissues decay down to the wood, or penetrates it, and, in 

 consequence, no fresh deposit can be made. I do not say it always 

 arises from a bud, whether developed or adventitious ; but I be- 

 lieve this very generally to be the case, and where the shoots are 

 thin and ill ripened the progress is extremely rapid. The same 

 process as before takes place ; new growth is formed round the 

 diseased patch, and a hollow gradually made as before. An old, 

 experienced gardener told me that he was careful to prune off 

 every spur which showed any symptom of decay, and never to 

 leave any decayed fruit where the peduncle had not separated from 

 the spur on the tree, as he had observed Canker often to arise in 

 this manner. "Where the diseased patches occur on the stem, if 

 they are cut out effectually, and the tissues protected from further 

 decay by some kind of paint, the disease may be arrested; but no 

 time must be lost, and every tainted shoot must be carefully re- 

 moved. If, however, the disease has arisen from the penetration 

 of the roots into ungenial soil, and not from stress of weather, 

 timely lifting and root-pruning is the obvious remedy. 



4. A fourth form of Canker I have observed on the Royal 

 Eusset, and it probably occurs on other varieties, though I have 

 not observed it elsewhere. The whole of the tender bark, for 

 several inches of the stem, looks as if it were pitted with the small- 



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