MILDEW. 



103 



Fig. 6. 



colour is different from the patches of bunt or smut fungus, 

 being, as above stated, yellow or orange, or rather varying 

 from orange-yellow to brown. In fig. 6 we give a sketch 

 of the sporules. Professor Henslow states, 

 with reference to rust, " that he believes 

 agriculturists have confounded under this 

 name, or the names we have above given, 

 the attacks of what systematic botanists 

 have distinguished as two distinct species 

 of fungi one of these we have named 

 above is the uredo rubigo, the other is 

 named uredo linearis" Of these two spe- 

 cies the Professor conjectures that whilst the spore of the 

 uredo rubigo undergoes no change, that of the uredo line- 

 aris is merely " the young state of a distinct form of spore 

 which, when further advanced, is called puccinm graminis." 

 9. Mildew. This last fungus, mentioned in preceding 

 par., is that which, according to Professor Henslow, pro- 

 duces the disease called the " mildew." The name pucci- 

 nia is given from a Greek word signifying thickly ; and so 

 called from the thick masses which infest the plants. The 

 common appearance of the straw of wheat attacked by mil- 

 dew is represented in fig. 7. The ripe spores are of an 



Fig. 7. 



Fig. 8. 



