ERGOT AND ERGOTISM 



351 



tacks various cereal and forage grasses. It is most commonly 

 known in the sclerotial or ergot stage as it occurs on rye. The 

 rye grain is replaced by the ergot "grain" or sclerotium. The 

 fungus may first be noted at the time of the flowering of the rye, 



Fig. 65. Stages in the development of ergot, Claviceps purpurea, on rye. A. 

 Ergot grains (sclerotia) appearing as dark spurs and replacing the rye grains. 

 B. Young infected rve ovarv, at whose surface conidia are formed. C. De- 

 tail of surface of young infected ovarv. D. Mature ascus of C. purpurea, 

 bearing eight thread-like ascospores. E. Diagram of apex of perithecial 

 stroma, showing perithecia arranged near the periphery. F. Sclerotium 

 in spring, bearing several club-shaped perithecial stromata. 



when the young rye ovaries are covered with masses of conidia 

 that collect in droplets. These droplets ("honey dew") are dis- 

 persed by insects. By the time the normal grain is ripe, the ergot 

 grains are also mature. When the grain is threshed, the ergot 

 grains are admixed with the rye. 



Ergotism in livestock. There is reason to believe that sclerotia 

 from all species of Claviceps are poisonous. From various parts of 

 the world have come reports of the poisonous effect of ergotized 



