RUSTS. 107 



di-morpiiisni_, is even stronger tlian against tlie 

 gi'oup just illustrated^ we cannot pass them altogether- 

 in silence, especially in a popular treatise. Those 

 who are residents in town_, and yet possess their 

 little plot of garden-ground, with only two or three 

 pet roses, may have had the misfortune of seeing 

 them smothered with a yellow blight. This golden 

 visitation, unwelcome as it is, may afford a subject 

 for the microscope, and for a small space in this 

 chapter. At first there will not appear to be any 

 important difference between the spores of the 

 yellow series of the last genus and those of the 

 present; but a closer examination will reveal one 

 important distinction, viz., the presence of colourless 

 elongated, abortive spores. The species are not so 

 numerous by half as those of TricJiobasis, even when 

 three anomalous forms are included, which species 

 are included by some mycologists in two other 

 genera. One very common rust of this group has 

 already been alluded to (plate III. fig. 37), and 

 which is known botanically as Lecythea Rosce. A 

 similar one is found on the bramble, and another on 

 the burnet. All these three species are produced 

 at first on spots which are afterwards more or less 

 occupied by the long, many-celled spores of th& 

 dark brown brands called Aregma or Phragmidiunif 

 between which and the simple yellow spores of the 

 rust almost every intermediate form may often be 

 found in the same pustule. Thus, from the same 



