56 



EEp-BOBIN. 



its appearance. Both these uredines are 

 clqsely aUied to the rust on the leaves of rose- 

 tre^s^ called uredo rosce. Their colour varies 

 from orange to a brownish hue, and they cause 

 the parts attacked to look as if they were 

 dusted with rustiness of these colours. They 

 belong to the order coniomycetes, or dusty 

 fungus. It is a rare thing to find any wheat- 

 field altogether free from them at any season 

 Qf the year. "\Vhen the chaff-scales are at- 

 tacked, the spots look 

 exactly as they are 

 represented in the 

 one here drawn, and 

 the matter forming 

 them exudes like a red 

 gum from the inner 

 surface. Hence red- 

 gum is a name some- 

 times given to it ; but 

 it is most frequently 

 known as red-robm, 

 red-rust, or red-rag. 



The chaff-scale de- 

 lineated here, gives no 

 ^v. ^ , xr . . u , , . further indication of 



Chaff-scale affected by red-robm, , , r • 



liighiy magnified. the character of this 



