RUSTS. 115 



of this species. In the remarks then made occurs 

 a recommendation of reperusal, which would ob- 

 viate any repetition here. 



An alKed species, and a beautiful one, is to be 

 found on the stinking iris {Iris foetidissima) , and 

 another on the under surface of the leaves of 

 primroses. 



The pilewort {Ranunculus ficaria) we have already 

 seen attacked by one species of microscopic fungi, 

 and we have now to record the occurrence of another. 

 Some plants appear to be destined both alive and 

 dead to become the prey of others. The common 

 nettle, for instance, as if in retribution for the 

 annoyance it often occasions on account of its 

 stinging propensities, has not less than twenty 

 different species of minute fungi, to say nothing 

 of coleopterous and lepidopterous insects, which 

 make a home, sometimes upon its green leaves, and 

 sometimes on its dead stems. We might almost 

 state that it has a flora and a fauna of its own. 

 The pilewort, too, has many foes ; but these are 

 fewer in number, and mostly attack the living 

 plant. The cluster-cups have been already noticed ; 

 some do not fall within the limits of this volume, 

 but one, which is found in May and June, belongs 

 to the present genus. It appears like a purplish- 

 brown powder bursting through blistered spots on 

 the leaves and footstalks (plate VII. fig. 156). 

 The spores are small, and are, of course, provided 

 with pedicels (plate VII. fig. 157). 



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