38 



of currant and gooseberry — the Summer Spores, and the Winter Spores. When 

 the Winter Spores are blo^^Ti to white pines in the vicinity they may adhere to 

 the bark of branches, and there germinate and penetrate the underlying tissues 

 of the bark. In a year or two the disease manifests itself by an increased thick- 

 ness at some point of the stem. In the spring fruiting bodies burst forth from 

 beneath the bark, and liberate large numbers of yellow (spring) spores. These, 

 when blown to leaves of currant or gooseberry, infect them and produce the char- 

 acteristic disease on these plants. 



Injury. — The injury to currants and gooseberries is not considered a serious 

 matter, but when an infected White-Pine is planted the fungus lives in the bark 

 until the tree dies. Most of the attacked trees die the first season that the fungus 

 fruits. Old trees are not liable to be attacked, and " the great damage is caused 

 by the dying of young pine trees in nurseries, plantations, and parks and those 

 naturally reproduced in the forests." So great has the damage been in Europe 

 that the growing of white pine has been discontinued in many countries. 



Control. — The only practicable method of control of this disease is to plant 

 White-Pine seedlings of American origin. In districts where the disease is already 

 present all currants and gooseberries should be removed from the immediate 

 neighborhood of the White-Pines. A rigid inspection should be made annually 

 for all traces of disease and any diseased trees should be immediately destroyed. 



