■310 MICROSCOPIC FUNGI. 



CHAPTER IX. 



EUSTS. 



A QUARTER of a century ago_, and all the fhngi 

 enumerated in tiie preceding and in the pre- 

 sent and following chapters would have been 

 an^anged under three genera, called respectively 

 JEcidium, Puccinia, and TJredo. Under the last- 

 named genus all the species illustrated in the pre- 

 sent chapter, beside many others, would have found 

 *' a habitation and a name/^ There are still a few 

 which bear the old generic name, and, if only out of 

 respect, we shall gi'ant them the first place. 



Let the first bright day in May witness the 

 student beside a cluster of plants of Mercurialis 

 jperennis, which it will not be difficult to find in 

 many localities, and, on turning up the lower 

 leaves, he will meet with our first illustration of 

 a genuine TJredo, in the form of yellow confluent 

 patches, with a powdery surface (plate VII. 

 fig. 133). This will be TJredo confluens. By the 

 way, the generic name is in itself suggestive, 

 which it always should be in all instances, but 

 unfortunately is not ; it is derived from the Latin 

 ivord uro, "I bum,^^ and is peculiarly apphcable 

 in instances where the leaves acquire a blistered, 

 burnt, or scorched appearance, occasioned by the 



