126 FORESTRY IN NEW ENGLAND 



the bark sometime between the middle of April and June, 

 according to the locality and the season. They are of a light, 

 orange color and project from the stem about one-eighth of an 

 inch. They soon break open and the spores are scattered by 

 the wind. After the spores are gone, the remains of the fruit- 

 ing bodies are washed off, leaving empty fissures in the bark to 

 show where they were. The spores from the pine, if they 

 chance to fall upon currant leaves, infect them in turn. On 

 these leaves in fifteen to forty days new fruiting bodies are 

 formed, the spores of which may infect either currant or pine. 

 The spores produced on the pine cannot directly infect pine, 

 but must first infect currants. On the pine the fungus remains 

 alive as long as the stem on which it grows; but in the currant 

 it is not thought to be perennial. Fortunately the spores are 

 not apt to be carried over one hundred yards. 

 The best means of combating the disease are: 

 (i) To examine all infested plantations and burn all currant 

 or gooseberry bushes, wild or cultivated, within five hundred 

 feet of the plantation. This should be done between the 

 middle of July and the fall of the currant leaves. 



(2) To inspect imported white pine trees and burn all that 

 show any symptoms of the disease; or better yet use only native- 

 grown plants. 



(3) To inspect, for two years at least, all white pines located 

 near infected currant bushes and burn all that become infected. 



White-heart Rot. False-tinder Fungus, Poplar Disease 



{Fomes igniarius)} 



The principal diseases of deciduous forest trees are caused by 

 a group of fungi which grow in the heartwood of trees. This 

 species is characteristic of the group. It is impossible to recog- 

 nize the presence of the fungus during the early stages of the 

 disease, in fact not until the fruiting bodies form on the exterior 

 of the trunk. When these appear the tree is thoroughly diseased 



1 See Bull. 149, U. S. Department of Agriculture Bureau of Plant Industry, 

 " Diseases of Deciduous Forest Trees." 



