100 MICROSCOPIC FUNGI. 



have a tendency to fold backwards at their mar- 

 gins, and thenceforth their growth seems to be 

 determined. Sowerby, in his " British Fungi/' 

 says : — " Two or three sorts of flies are occasion- 

 ally found dead on this plant at the time of the 

 fungus being upon it, which is after wet weather in 

 the summer, or early in autumn ; being apparently 

 tempted by its flavour, they over-eat themselves, 

 or else are destroyed by some poison." This rust 

 has spores resembling, in general characters, those 

 of the yellow-spored series (plate VII. fig. 152). 



We have not thought it necessary to give figures 

 of many species, partly on account of the uncer- 

 tainty existing in many minds whether they ought 

 to be regarded as species, and whether they will 

 long claim a place in the British Flora; and partly 

 on account of the similarity which exists between 

 them, at least so far as they are of interest to the 

 microscopist only. 



During the autumn of 1864, whilst on a botan- 

 ical excursion through a portion of Epping Forest, 

 the ' ' great bog " became a centre of some interest. 

 Bogs are generally attractive spots to those who 

 are in search of microscopic organisms. On this 

 occasion the chief objects of interest were the 

 small brown pustules (plate VIII. fig. 168) with 

 which the upper surface of a large number of the 

 leaves of the pennywort (Hydro cotyle vulgaris) were 

 sprinkled. These pustules were brown, orbicular, 

 regular, and in habit seemed to resemble rather 



