CALYPTOSPORA 333 



(Jepson), in the United States. Diseased cowberry plants 

 present a very striking appearance; the stem is the part 

 attacked. All the branches grow perfectly erect ; the entire 

 plant grows much taller than healthy plants, and the leaves 

 are stunted. The stem becomes much swollen and spongy 

 in texture, and is at first rosy-pink, changing to brown, then 

 blackish. The teleutospores are produced in the epidermal 

 cells of the swollen portion. 



Aecidiospores globose or elliptical, warted, orange, 16- 

 22x10-16 /*. Teleutospores, cuboid-globose, generally 

 4-celled, brown, smooth, up to 30 //, long. 



If young conifers happen to be growing near to a diseased 

 cowberry plant, the secondary spores from the latter that 

 alight on the conifer leaves set up the aecidium stage, 

 whereas, in turn, the aecidiospores infect neighbouring cow- 

 berry plants. 



If cowberry plants are growing apart from conifers, the 

 teleutospore stage alone continues to grow and reproduce 

 itself without the intervention of the aecidium stage. On the 

 other hand, the aecidium stage cannot maintain an isolated 

 existence. 



The silver fir, in its young condition, suffers most in this 

 country and in Europe. Diseased specimens of A. nord- 

 manniana have also been received at Kew from Wales. 



Preventive measures are alone of service in combating this 

 disease. In selecting a site for a seed-bed or nursery, it is 

 important to ascertain first that no diseased cowberry plants 

 are growing in the neighbourhood. Such can be readily 

 detected when growing amongst healthy plants from the 

 description given above. The same rule applies when young 

 conifers are planted in woods. If diseased plants are not 

 numerous, they may be removed and burned. 



Hartig and Somerville, Diseases of Trees > p. 159. 

 Massee, Kew Bulletin, No. i, p. i (1907). 



Cinerarea leaf rust. Mr. F. A. Chittenden has recently 

 described the presence of a rust (ColeospoHum senedonis^ Fr.) 

 on the leaves of Cineraria. Infected leaves show small, 

 yellow, powdery patches scattered in greater or less abundance 

 on the under surface. These patches of uredospores are 

 followed by the resting or teleutospore form of the fungus. 

 The aecidium stage, once known as Peridermium pini, occurs 



