Witches Brooms on Trees 



533 



duced on their under surfaces. We must admit, however, 

 that the damaged branch had by no means developed a well- 

 characterised " broom." The fungus was the JEcidiutn 

 elatimim. What had been caused was a breaking up of the 

 bark at the site of attack, and beyond this the branch was 

 thickened, as is usual when the return of sap is hindered, and 

 the branches were much multiplied, but it could not be said 

 that they grew a good " broom." 



It is possible that some of the best " brooms " are caused 

 by the attacks of mites which persist in their occupancy and 

 attack the spring buds every succeeding year. 



As we have just remarked, brooms are very seldom seen on 

 oaks. The oak is, however, prone to produce what may be 

 called " witches' scrubbing brushes." In the condition which 

 may be so named, an area, the size, perhaps, of the palm of 

 one's hand, is thickened by a flattened core of wood from 

 which spring innumerable short twigs, but few of them more 

 than an inch or two high. These may be found very fre- 

 quently on oaks, and if there is one there are usually many 

 on the same tree. We have in the Combeswell Copse (near 

 Haslemere), a small oak, probably thirty years old, on which 

 from thirty to fifty of these brushes may be counted. They 

 begin near the ground and are seen twenty or thirty feet up. 

 The trees near to it are for the most part almost free. This 

 remarkable aptitude of certain trees to produce " brushes " or 

 -"brooms" in great abundance, whilst the majority of their 

 neighbours do not grow any, may be allowed to illustrate the 

 fact that the production is far more closely connected with 

 the proclivities of the tree than with the nature of the parasitic 

 injury. Our illustration shows the remarkable abundance of 

 brooms on a birch tree, and plenty of similar instances may 

 be found. Perhaps, however, in copses where birches abound, 

 not one in a thousand grow any brooms. Like the oak many 

 birches produce " scrubbing brushes," but usually these occur 

 only near to the ground. 



The attacks of the mite which is supposed to be responsible 

 43 



