58 MICROSCOPIC FUNGI. 



termed a genus, and the term prefixed to the specific 

 name of each species constituting that genus is its 

 generic name^ also commonly derived from the 

 Latin or Greek. In this instance it is Puccinia, 

 derived from tlie Greek pul^a, meaning closely 

 pacTied, singularly applicable to the manner in 

 which the spores are packed together in the pus- 

 tules. The common features^ or generic distinc- 

 tionSj of this genus_, are uniseptate spores borne on 

 a distinct peduncle. 



In retm-niug to the species found on Labiate 

 plants^ let us suppose ourselves to have strolled 

 towards Hampstead Heathy and south of the road 

 leading from Hampstead to Highgate_, near certain 

 conspicuous and well-known arches_, built for a pur- 

 pose not yet attained^ are two or three muddy 

 ponds nearly choked up with vegetation. Some 

 fine autumnal afternoon, we must imagine om^selves 

 to have reached the margin of the most northern of 

 these ponds, and amidst a thick gi'owth of reeds, 

 sedges, and other water-loving plants, to have 

 found the water-mint in profusion and luxm-iance, 

 with every leaf more or less occupied, on its under 

 surface, with the yellow spores of a species of rust 

 [Trichohasis) mixed with the browner septate spores 

 of the mint brand {Puccinia Menthce). This is com- 

 mon also on the horse-mint and corn-mint ; we 

 have found it on the wild basil and wild thjTne, 

 and once only on marjoram. Having collected as 

 many leaves as we desire, and returned to home 



