wintered fields, and on those on the edges of fields. It is also found 

 on late shoots, whose glumes, because pollenation fails, remain open for 

 a week or more. 



The vi^eather not only affects the degree of infection hut 

 also the amount of ascospore formation and the extent of ascospore dis- 

 semination. The ascospores are throvsn out copiously in hright, \varm weather, 

 are lifted up from the damp places where they are produced by ascending atmos- 

 pheric currents and are parried by the wind. Damp weather is necessary for 

 the ripening of the ascospores and dry weather for their diseemination. Even 

 though such damp and thendiy weather has brought numerous spores into the 

 atmos^ere in July and August, if the season has not been sufficiently damp 

 to make the grasses taller and draw up late spikes, there will be less 

 ergot because of tho smaller number of flowers to be ergotized. A season 

 which is at once favorable to Claviceps and to the production of late 

 flowering grasses is, according to Wilson (299) required for the largest 

 development of ergot in Scotland. Edwards Carroll (27), contrary to the 

 views of other authors, says that ergot is rare when the season is wet, 

 frequent when it is dry. This, he explains, is due to the fact that in 

 Ireland, where he made his observations, the moist atmosphere is enough 

 for the germination and successful establishment of the fungus, while rain 

 would wash the spores off the plants and a superabimdance of water would be 

 unfavorable to their growth. On the continent, where the atmosphere 

 is diy, rain may be necessary for its grov/th, according to Carroll. 



The topograpihy of the field, the drainage, the shading, the 

 soil conditions and the time of planting have also been associated by some 

 men with the degree of ergot infection. Pammel states that ergot flourishes 

 particularly well on rich soil and in warm, damp seasons (190). It is a 

 well known fact that ergotized grasses are m.ore apt to be found in the low 



