CLAVICEPS 



223 



Ergot. This well-known disease, caused by Claviceps 

 purpurea (Tul.), is often developed in the ears of various 



FIG. 64. Claviceps purpurea. i, ergot on rye-grass; 

 2, ergot on rye ; 3, section of portion of conidial fruit ; 

 4', sclerotium or ergot bearing the stalked, ascigerous form 

 of fruit ; 5, head of ascigerous fruit showing warted surface, 

 due to projecting mouths of perithecia ; the section shows 

 perithecia sunk in the fleshy stroma ; 6, ascus ; 7, free 

 needle-shaped spore. Figs, i, 2 and 4 nat. size ; remainder 

 variously mag. 



cereals, especially rye, also in the inflorescence of many kinds 

 of grasses. Infection takes place when the plants are in 

 bloom, the mycelium developing in the ovary, replacing the 



