290 GARDEN FOES. 



natural functions, and it should therefore be prevented 

 from spreading to healthy foliage. 



Eemedies. — Gather and burn all the fallen leaves in 

 autumn, before the spores have time to ripen and liberate 

 themselves. 



Witches' Brooms — A popular name for the bundles 

 or bunches of twiggy, mistletoe-like growths often seen 

 on the silver birch tree. These peculiar growths are 

 formed in the first instance by a fungus called Exoascus 

 tm-gidus. The fungus first attacks the leaf and then per- 

 meates the tissues of the shoot. Each year, as new shoots 

 are developed from the first one, the fungus spreads, so 

 that in time quite a tangled nest-like bunch of twigs is 

 produced. A similar growth appears on cherry trees. 



Remedy. — Cut away the mass of growth entirely. 



