220 DISEASES OF FIELD & GARDEN CROPS. [CH. 



purple globose heads. Externally they are irregularly 

 dotted over with little prominences, as at Fig. 101, A, 

 enlarged five diameters ; and in this they greatly resemble 

 the clubs belonging to Torrubia found growing upon a 

 buried truffle (see Fig. 22). On cutting longitudinally 

 through the head of the Claviceps of ergot we find it like 

 the parasitic growths belonging to the truffle (and unlike 



the potato Peziza illustrated 

 at Fig. 7). We see it, if 

 enlarged twenty diameters, 

 as at B, Fig. 101, packed all 

 round its outer surface with 

 small flasks, conceptacles, or 

 perithecia, with the mouths 

 of the flasks all opening 

 towards the outside. The 

 little projecting mouths, as 

 at CC, represent the minute 

 prominences seen on the 

 outside of the cap or stroma 

 at A. As with the former 

 fungi we have described, we 

 must now cut an extremely 

 thin transparent slice off 

 the exposed cut surface of 

 the head, and magnify with 

 the highest powers of the 

 microscope to make out the 

 nature of one of the minute 

 conceptacles or perithecia 

 and its contents. 

 If we magnify a single perithecium or conceptacle 200 

 diameters, we shall see it as at Fig. 102. We now notice, 

 as in former examples, that the flasks, conceptacles, or 

 perithecia are closely packed with fine long transparent 

 bladders, which spring from the base of the perithecium. 

 The mouth from which these bladders ultimately emerge 



X ZOO 



FIG. 102. -Section through a concep- 

 tacle or perithecium of Claviceps 

 purpurea, Tul. Enlarged 200 

 diameters. 



