20 



ON ERGOT. 



ports (sterigmata) of oblong cells (spennatia or conidia), the most of 

 whicli are free in the drawing. These cells are the spores of the 

 Ergotetia of Quekett, and the Oidium of Berkeley and Broome. The 

 oblong cells or " spores," when placed in water, freely germinate {a), 

 and they have the power of reproducing the parasite. Bat we have 

 not here the perfect condition of the plant. Recent observations have 

 shewn that many fungi produce at different stages of their history free 



Fig. 7. 



cells possessed with the power of germination. The spermatia-bearing 

 stage has been observed in other fungi besides the ergot. 



When the ergot attains iis full size the sphacelia disappears, or 

 only the withered and diied up remains of it can be detected at the 

 apex of the ergot. 



The further history of the ergot has been determined also by 

 Tulasne. The frequent occurrence of minute Sphajrias on the ergotted 

 grains of grasses- suggested to him that they were probably not acci- 

 dental productions, as had been supposed, but were organically con- 

 nected with the ergot, and represented a further stage of its develop- 

 ment. AYith the view of testing this opinion, he planted a number of 

 ergotted grains, and had the satisfaction to find that a considerable 

 proportion produced Sphaerias. Those produced by the ergot of rye 

 were the same in form and structure with what were grown from the 

 ergots of most of the other grasses, and believing them all to belong to 

 the same species, he gave to it the name of Claviceps purpurea (Fig, 8). 

 This perfect plant is a small purplish fungus, with a spherical head, 

 supported on a short firm stem, with a somewhat downy base. The 

 globose head is rough with small prominences, which are the openings 

 of the civities or conceptacles in which the spores are produced {b and 

 c). One of theso conceptacles, highly magnified, is shown in Fig. 9, «, 



