FUNGI IMPERFECTI 



333 



bird's-eye spots, or effects, are produced. At first ashen-brown 

 spots appear, and as these enlarge in a more or less regular man- 

 ner the central portion becomes sunken, and between the paler 

 central portion and the brown outer border a band of red or red- 

 purple is apparent. The unaffected portion of the berry remains 

 perfectly green, but the spot may at times embrace eventually the 

 entire berry. When the shoots are affected the spots are similar 

 to those on the fruit except that they elongate in the direction 

 of the axis, becoming prominently sunken, pale at the center, and 



Fig. 159. Glceosporium ampelophagum: Anthracnose of Grape 



always less highly colored. The young leaves are also affected with 

 spots with pale centers and brown-red borders. 



The acervuli of the fungus appear more commonly upon berries 

 and twigs. The fungus resembles very closely, in general, other 

 species of Glceosporium. A large number of minute conidiophores 

 are produced, each of which may originate many conidia. The latter 

 may be elliptical, ovate, oblong, or even slightly constricted at the 

 middle portion. These are usually 5-6 x 2.5-3.5 /x. By some it 

 has been claimed that the anthracnose of the grape is the same 

 fungus as that producing the bitter rot of the apple, but this is 

 probably incorrect. It is quite probable that a ripe rot of the grape 



