EUTYPELLA 171 



The mycelium spreads rapidly in the cane, and such were 

 at one time used for propagation ; this is disastrous, as the 

 disease grows along with the cane. It was also the custom 

 to have diseased canes lying about. This should not be 

 done, as the spores produced on these infect growing canes. 

 Only perfectly healthy canes should be used for propagation. 



Massee, Ann. Bot., 7 (1893). 

 Went, Ann. Bot., 10, p. 583 (1896). 



EUTYPELLA (Nits.) 



Stroma valsoid, immersed in hard bark or wood, bounded 

 by a black line ; perithecia in one or two strata, sometimes 

 circinate, mouth sulcate ; asci long-stalked, 8-spored ; spores 

 tinged yellow or hyaline, continuous. Conidia and spermo- 

 gonia often present. 



Stem disease of young fruit-trees. Young standard fruit- 

 trees, more especially apple, pear, and plum, are often killed 

 outright by a fungus called Eutypella prunastri (Sacc). 

 Almonds, cherries, peaches, and apricots suffer to a lesser 

 extent, but do not always escape. The variety of plum called 

 'Victoria' appears, so far as I have observed, to be most 

 susceptible of all to the disease. The stem or larger branches 

 are attacked, and a tree almost invariably dies the second 

 season after the disease shows itself outwardly, infection 

 having taken place the year previous. The first suggestion 

 of the presence of the fungus is the occurrence of slightly 

 shrunken areas of the bark, which look dry and dead. These 

 diseased areas gradually extend until the stem is completely 

 girdled, and presents a ' bark-bound ' appearance. The dis- 

 eased bark soon becomes covered with myriads of minute 

 raised points, which are the openings of receptacles embedded 

 in the bark, and containing the conidial form of fruit of the 

 fungus. At this stage the mycelium has killed the cambium 

 and entered the wood, choking the vessels and preventing the 

 upward passage of water from the roots. When this stage 

 has been reached the tree dies the following season, after 

 making an attempt at producing leaves. In some instances, 

 where the stem has not been completely girdled by the 

 disease, it may continue to live for another year, but the 

 scanty yellow, wilted foliage clearly indicates that the end is 



