142 



DISEASES OF CROPS. 



Cure. — See those already described for destroying P. 

 infestans (the potato-disease fungus). 



The Fusisporium of Cabbages {Fusisporium 

 aurantiacum) has a similar life-history to F. solani 



Fig. 47. — White Bust Fungus of Cabbages (Cystoput candidus). 



A. Mycelium bearing conidia. x 195. 



B. Conidium (zoosporangium) producing zoospores, x 405, 



C. Oogonium (1) and antheridium (2). x 195. 



D. Oospore (resting-spores). x 195. 



E. Inner membrane of oospore containing zoospores, x 105. 



F. Zoospores, x 405. 



b and /, Zoospores germinating. 



{M.agnijlcaiwn6 according to Znss.) 



already described. It infests the leaves and stems of 

 the host-plant. 



The White Rust of Cabbages {Cystopus candidus, 

 rig. 47) causes no inconsiderable amount of damage, in 

 certain seasons, to cabbages, cauliflowers, and allied crops. 

 This disease is known by the swollen leaves, stems, etc. 



