XXVIII.] 



CLAVICEPS ON ERGOT. 



235 



normal variety. The Claviceps grows from the interior of 

 the ergot, and bursts through cracks on the surface. Some- 

 times the crack or opening is very small, and through this 

 small opening the Claviceps emerges 

 and speedily produces a matted base 

 of mycelium upon the surface of the 

 ergot, before the club is produced. 

 In some instances the base of spawn 

 is so thick that the Claviceps super- 

 ficially resembles a parasite upon 

 ergot rather than a true fruiting 

 condition of ergot itself. Some- 

 times this effused mycelium spreads 

 over the ergot, and several clubs 

 arise from one stratum of mycelium, 

 which may have emerged from one 

 minute hole or crack in the black 

 ergot or Sclerotium. The pales of 

 the grass flower are shown attached 

 to the ergots in Fig. 108. 



The upper part of a club is illus- 

 trated at Fig. 109, enlarged twenty 

 diameters, for comparison with the 

 normal club of Claviceps purpurea, 

 Tul., illustrated to the same scale 

 at Fig. 101, B. It will now be 

 noticed that the perithecia or con- 

 ceptacles are, on the average, the 

 same in size and character in both 

 fungi, the only difference being 

 that the club is drawn up in the FlG m _ Upper part of 

 variety Wilsoni, W.Sm., and its soft 

 substance is drawn away from the 

 perithecia, which are left almost 

 free instead of being embedded as in the typical C. pur- 

 purea, Tul. A phenomenon of this class is one of the 

 commonest in the vegetable kingdom, and is especially 



Claviceps piirpurea, Tul., 

 var. Wilsoni, W.Sm. En- 

 larged 20 diameters. 



