94 THE HEALING OF WOUNDS 



"In Germany the large, fleshy, sulphur -yellow 

 punk -fungus, Polyporus sulphureus, is known to 

 have attacked and caused decay of pear trunks, 

 gaining an entrance through a wound. This 

 fungus occurs in America, and while it is not 

 reported on orchard trees, I have found it grow- 

 ing luxuriantly upon the wild cherry, Prumis 

 serotina, killing the trunk, apparently, for a con- 

 siderable distance below a dead branch. 



"The common little agaric, Schizophyllum com- 

 mune, I have observed growing in clusters be- 

 tween the new bark and the dead wood on an 

 apple tree to which the knife had been severely 

 applied after sun -scorching, but this fungus 

 doubtless only aids decay. 



"Among pyrenomycetous fungi, there are some 

 which may take advantage of the injuries from 

 pruning. In Europe, Nectria ditissima is known 

 on the apple and bird cherry, producing on the 

 smaller branches the characteristic canker spots. 

 This fungus must enter through abrasions or 

 pruning wounds, and the decay which follows is 

 often considerable. Nectria cinnabarina is an- 

 other one of these fungi, common in this country 

 on many hosts, and this I observed last year on 

 a large branch of pear, extending to a considerable 

 distance either way from a broken branch of 

 small size. 



"Rots and decays as a result of pruning de- 

 serve more attention, in order that we may 



