ECONOMIC IMPORTANCE OF FUNGI 29 1 



imported from foreign countries. Sometimes whole 

 cargoes of potatoes or other vegetables are refused en- 

 trance at the port, and must then be taken to sea and 

 dumped into the ocean, or else taken to the port of some 

 other country where the regulations are less stringent or 

 less rigidly inforced. 



282. Diseases Caused by Phycomycetes. — Among the 

 plant diseases caused by the alga-like fungi may be 

 mentioned: 



Fig. 213. — "Little potatoes." A disease caused by the parasitic fungus, 

 Rhizodonia {Corticium vagum var. solani Burt). 



1. The ''damping-off fungus" {Pythium de Baryanum 

 Hesse), which attacks young seedlings of beans and other 

 plants near the surface of the ground, causing the tissues 

 there to disintegrate, and the entire plant finally to wilt 

 and die. 



2. Brown rot of lemons, commonly seen in fruit that 

 has been kept too long or in too damp a place. 



3. *' Blister-blight" or white ''rust" of radishes and 

 their relatives, such as shepherd's purse and mustard. 



