744 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



of a disease, for the sake of the amount of manure to be obtained from 

 Potato-tops or dead bean-stalks. 



The weeds of gardens, fields, and hedgerows also have their fungus 

 parasites, and these have been known to pass on to cultivated plants ; 

 hence the feww weeds the less risk of an epidemic. 



The large fungi that attack fruit and other trees can only gain an 

 entrance through some w^ound. Branches broken by wind or other 

 means should be removed and the cut surface coated with gas- tar ; and, 

 more especially, great care should be taken not to wound the base of the 

 trunk or projecting roots with the spade, grass-cutting machine, &c. 



With regard to mulching, the two dangers are — the introduction of 

 resting- spores or sclerotia along with the manure ; allowing the manure 

 to remain unmoved until it becomes compact and sodden, thereby 

 preventing free access of air to the soil, and sourness is the result. 



In pruning, the greater the number of cut surfaces protected by a coat 

 of gas-tar the less is the risk of infection. An interval of several, even 

 many years may elapse between the entrance of a parasitic fungus into 

 the tissues of a tree, through an unprotected wound, and the evidence of 

 any injurious action on its part ; yet all this time it may have been quietly 

 extending its mycelium, and during some temporary check to growth on 

 the part of the tree manifests itself in a very unpleasant manner. 



