COWBERRY SCLEROTINIA 153 



stems. Fresh stable manure on the surface of the soil 

 greatly favours the spread of the disease. 



De Bary, Bot. Ztg., p. 458, 1886. 



Potter, y<?^/;;7/. Board Agric, vol. iii. No. 2, figs. 



COWBERRY SCLEROTINIA 



{Sclerotinia ur?iida, Rehm. 

 =-Sclerotinia vaccinii, Wor.) 



During the early part of summer the leaves and young 

 stems of the cowberry ( Vaccinium vitis-idaed) often show 

 dark-brown patches or stains, which soon become covered 

 with a snow-white delicate mildew, which often assumes a 

 yellowish tinge when old. This mildew, the conidial or 

 summer form of fruit of Sclerotinia urnula^ when examined 

 under the microscope, is seen to consist of simple or 

 branched chains of conidia, arranged like a string of beads. 

 As the conidia become mature, the narrow neck connecting 

 adjoining conidia undergoes a peculiar change in form and 

 structure, which results in the conidia assuming a lemon- 

 shaped form, and becoming free from each other. The 

 mature conidia have a strong smell, resembling almonds, 

 that proves very attractive to insects, who, along with wind, 

 convey the conidia on to the stigmas of the Vaccinium 

 flowers. These conidia germinate, the germ-tubes passing 

 down the style into the ovary, where the hyphae forms a 

 sclerotium in the interior of the fruit. Such diseased 

 fruits fall prematurely, lie on the ground throughout the 

 winter, and in the spring one or more dark brown, wineglass- 

 shaped ascophores grow^ from the sclerotium contained 

 within the mummified Vaccinium fruits. 



