22 HAY AND FODDER. 



they ripen. Examined microscopically they are seen to 

 be covered with pores each leading to a flask-shaped 

 cavity in the body of the head. These cavities contain a 

 number of asci. In each ascus are eight threadlike 

 spores, the ascospores. These are discharged at the time 

 when the host plant is in flower. Falling on the young 

 ovary of the flower, the spore germinates producing 

 fungous filaments (hyphae) which enter, feed upon, and 

 displace the soft tissues, ultimately forming another 

 sclerotium. Before hardening, however, the fungus 

 passes through the Spho.celia stage, in which a sweetish 

 liquid called honey-dew is secreted, and numerous small 

 spores known as conidia are formed and cut off from the 

 free ends of the hyphae. These are carried to other plants 

 by insects attracted by the fluid, and so the Ergot is 

 spread throughout the field, since each spore which 

 reaches another young ovary may germinate and infect 

 that grain. 



Rye is more often attacked than other cereals, and it 

 is from this plant that the ergot used in medicine is ob- 

 tained. Wheat is sometimes ergotized, however, and oats 

 containing the fungus have been reported. In addition, 

 this fungus, or possibly a closely related species having 

 the same effects, is found on a large number of 

 grasses of wide geographical distribution. The follow- 

 ing are species affected : 



Agropyron Smithii Rydb. Western Wheat Grass 



Agropyron repens (L.) Beauv Couch Grass 



Hystrix Hystrix Millsp Bottlebrush Grass 



Elymv.s canadensis L \ 



" robustus Scribn. & J. G. Sm. ... , 



" striatm Willd. I Wlld Rye 



" virginicus L 



