444 PROTECTION AGAINST FUNGI. 



the chief infectors. The uredospores appear on the lower 

 surface of the leaves of these plants, at the beginning of June, 

 as small yellow cushions. The teleutospores that arise from 

 them are brown and in rows. The sporidia that come from 

 them and germinate on the Weymouth pine, cause swellings, 

 in which a mycelium grows, and next spring, spermagonia are 

 formed, and secidia later on. Species of liibes are again 

 infected, and the disease becomes widely spread. The fungus 

 on the Ribcs is named Cronartium ribicolum, Dietr. 



b. Subjects of Attack. 



The fungus attacks young plants and poles of Weymouth 

 pine, chiefly on their stems. It also attacks lateral branches 

 of older trees; tree-parts older than 20-25 years appear to 

 escape. 



In 1880, about 30 per cent, of the Weymouth pine in 

 Bremen Town Park were attacked and seriously injured by 

 this fungus. The disease has also appeared in other districts 

 in N. and S. Germany and in Denmark. It is reported to 

 have originated on Cembran pine (?) in the Baltic provinces. 

 It has not yet been noticed in America, the home of the 

 Weymouth pine. 



c. Protective Measures. 



i. Secure healthy plants of Weymouth pine, when buying 

 from nurserymen. 



ii. Eemove and burn all infected plants. 



iii. Cut out infected poles in thinnings. 



iv. Do not allow any species of Biles to grow within at 

 least fifty yards of Weymouth pine plantations. 



*7. Melampsora pinitorqua, Rostrup. 



(Pine Branch-twist.) 

 a. Description and Mode of Attack. 



This fungus, formerly named Caeoma pinitorquum, A. de 

 Bary, is developed, especially in North Germany, in the cortex 

 of the young shoots of the Scots pine. Before they have 

 attained their full length, at the end of May or beginning of 



