444 PROTECTION AGAINST FUNGI. 



the chief infectors. The uredospores appear on the hwev 

 surface of the leaves of these phmts, at the begmiiing 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 .necidia later on. Species of Rihcs are again 

 infected, and the disease becomes widely spread. The fungus 

 on the liihes is named Cronartium ribicolum, Dietr. 



b. Suhjeris 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 Measiirpft. 



i. Secure healthy plants of Weymouth pine, when buying 

 from nurserymen. 



ii. Remove and burn all infected plants. 



iii. Cut out infected poles in thinnings.- 



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

 least fifty yards of Weymouth pine plantations. 



*7. M(l<aiiji.snra pinitorqua, Rostrup. 



(Pine Branch-twist.) 



a. Desrriiition and Mode of A ttaclc. 



This fungus, formerly named Cacoma innitorquum, 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 



