VALSA. 225 



where leaves of the alder are dried in summer for use as 

 winter-fodder for goats. 



In the branches attacked, a mycelium is developed in the 

 vessels of the wood, whereby the supply of water is stopped 

 and the bark dries up. Black lens-shaped stromata arise 

 under the epidermis of the twig and rupture it. The perithecia 

 are produced under the stromata in the bark, and communicate 



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FiG. W9.— Valsa o.ri/stoma on Alnus viridi*. A, Portion of branch with stroma 

 of Valsa breaking through the periderm at four places. B, EnLirged section 

 through a stroma from A. C, Asei and ascospores, isoLited from a porithecium. 

 Z), Portion of younger branch with periderm ruptured by .stromata, in which, 

 however, the perithecia are not yet developed. E, Enlarged section tlirou>.'h :i 

 stroma of D. (After v. Tubeuf.) 



with the exterior by means of long projecting necks. llie 

 asci contain eight unicellular spores of a slightly bent, rod- 

 like shape. Maturity is reached on the dry dead twigs. 

 Externally this disease is identical in appearance with one 

 I ascertained to be due to a beetle {Cryiitorhynchm lapathi), 



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