82 MICEOSCOPIC FUNGI. 



exceedingly common. In a field or wood tlie my- 

 cologist reaps his richest harvest of mycological 

 specimens in the lowest and dampest spots_, in 

 swamps_, ditches^ and ill-drained nooks. This is a 

 fact worth knowing as much by the farmer as the 

 amatem" botanist in search of specimens for his 

 herbarium. 



One of the most unmistakable species of '' smut ^' 

 is that which infests the goatsbeard^ on which we 

 have already described an j^cidium. Generally 

 about the same time as the cluster- cups make their 

 appearance on the leaves_, some of the unopened 

 flower-heads of this plant will be found considerably 

 altered in appearance by the shortening of the seg- 

 ments of the involucre, and at length by the whole 

 inflorescence being invested with a copious pui'plish- 

 black dust. If, by any means, the lobes of the invo- 

 lucre are any of them separated, the enclosed dust 

 escapes, blackening the fingers and clothing of the 

 collector, as if it were soot (plate Y. fig. 92). A little 

 of this dust submitted to the microscope will be found 

 to consist of myriads of small globose spores, nearly 

 uniform in size and shape ; and if a higher power 

 be .employed, each of these will appear to have a 

 papiUose or minutely granulated surface. The 

 florets, dwarfed in size and contorted, or the remains 

 of them, are embedded in the mass of spores (fig. 93), 

 and if one or two of these are removed and placed 

 under a good one-inch objective, every part will be 

 found covered with adhering spores, to the apparent 



