FIG. 123. The White Rust of Cruciferae (Cystopus candidus). A, Diseased 

 inflorescence of Shepherd's Purse, showing the white patches where 

 the gonidia of the Fungus are being formed. B, Hypha (A.) with haus- 

 toria (5.), as seen in a longitudinal section between the cells (Ce.) of 

 the host . C, Transverse section near surface of host, showing hyphae (h . ) 

 and gonidia (Sp.}. D, Antheridium (a.) and oogonium (o.) (after De 

 Bary). E, The same in section at the time of fertilisation (after 

 Stevens). F, Germination of oospore (after De Bary). G, Zoospores 

 (after De Bary). (Figs. A-C, original.) 



233 



