132 



Minnesota Plant Diseases. 



giving rise to a 

 dust of wliite 

 spores at the sur- 

 face of the 

 ground. These 

 spore-forms have 

 all been described 

 as of separate and 

 inde p endent 

 plants. They 

 seem to be able to 

 infect the insects 

 just as do the sac- 

 spore cells. These 

 fungi are thus 

 seen to be very 

 similar to the er- 

 got fungus in all 

 essentials but the 

 accessory spore 

 forms are more 

 numerous and are 

 found under dif- 

 ferent conditions 

 than are those of 

 the latter. (Figs. 

 ID, IS, 31, 56.) 



Strangling fungi 

 (Hypocreacea in 

 part). On a few 

 grasses in the 

 state occurs a fun- 



FiG. 67. — A strangling 

 fungus on grass leaves 

 and stems. A few 

 leaves extend above the 

 fungus fruiting body, 

 but the growth of the 

 host is usually stopped. 

 The surface of the fun- 

 gus fruiting body is 

 covered with warts 

 which are the ends of 

 the spore-sac-capsules. 

 Original. 



