274 



PLANT DISEASES 



inoculated, to secure for the fungus a foothold from which 

 it can attack neighbouring plants, and, in the course of the 

 season, victimise most or all the plants in the neighbour- 

 hood. 



Fig. 71.— Vermicularia circinans. i, onion 

 attacked by Verviicularia ; 2, one of the black 

 tufts of the fungus, x 50 ; 3, portion of a tuft show- 

 ing the curved conidia borne at the tips of slender 

 threads or conidiophores, also the long black 

 spines, X 250. 



Berkeley, Gard. Chron., 1851, p. 595, figs. 

 Stoneman, Bot. Gaz., i8g8, p. 98, fig. 16. 



