276 [ DISEASES OF THE APPLE TREE 



produces larger spots or blotches of a brown colour, not 

 surrounded by a particular edging. Asteroma geographi- 

 cum Desm., Vermicnlaria trichella Fr., and Stigmatea 

 Mespili Sor. attack the leaves of the apple in the same 

 way as those of the pear. Gymnosporangium clavariaejorme 

 Jacq., attacks the leaves and the fruit of the apple, and 

 G. juniperinum Fr. attacks the leaves of the apple as 

 well as those of the quince, but these two fungi have not 

 been detected in our orchards, nor are they likely to 

 make their appearance in these Islands owing to the 

 absence of the Juniper, their intermediate host. 



Three species of Phyllosticta attack the leaves of the 

 apple. Ph. Briardi Sacc. forms small irregular spots 

 of a brown or chocolate colour, which penetrate the 

 substance of the leaf and are visible on both surfaces. 

 Ph. prunicola Sacc. produces larger dry spots or blotches 

 often surrounded by a darker edge, on the upper surface 

 of the leaf, and later on the blotches develop minute 

 black dots, \\hich are the fructifications of the fungus. 

 Ph. Mali Prill, et Delacr. produces small brown spots 

 which afterwards become grey, with a thickened dark 

 border, on the upper surface of the leaf. 



Hendersonia Mali Thlin. is met with along the 

 Adriatic, and produces large round, grey blotches sur- 

 rounded by a violet margin. A rare continental fungus is 

 Pistillaria maculicola Fuck, and the lesions produced by 

 it consist in large dry blotches which gradually invade 

 the whole leaf On the undersurface are developed the 

 fructifications in the form of minute club-shaped recep- 

 tacles borne on white pedicels. As a preventive measure 

 collect and burn all diseased leaves as soon as possible, 

 giving no time to the fungi to spread or to form hyber- 

 nating centres. 



Capnodium salicinum Mtge. is a sooty fungus rather 

 frequent on apple trees suffering from an attack of 

 Aphis or of scale. 



