244 



GARDEN FOES. 



greater damage before detected than the powdery mildew. 

 It is likewise less easy to eradicate, because it thrives 

 within the substance, while the sphierotheca feeds super- 

 ficially. This fungus causes the leaves to fall off sud- 



BLACK LEAF-SPOT. 



1, I?()60 lear infe^sted with the fiingue, natur;il sizv; 2, Tlireads creci)in<>" over 

 the black «pote. and bearing the fruit, nuiltiplied by 80; 3, Spore* of the fungus 

 contained in the fruit borne on the white threade multiplied by 4C0. 



denly, and the young shoots to turn black and die. It 

 attacks roses grown under glass, and in the case of a bad 

 attack often seriously cripples the growth. 



