WHITE MILDEWS OE BLIGHTS. 177 



occurring on straw, tile most common one is figured, 

 natural size, in our plate (fig. 267) ; but from this 

 no idea can be formed of its structure, whicli in 

 some points resembles an Erysiphe. The concep- 

 tacles are thiu and brittle, and are clothed ex- 

 ternally with long dark-coloured branched hairs 

 (figs. 258, 259). The conceptacle contains long 

 narrow sporangia, each enclosing dark, almost 

 black, lemon-shaped sporidia. For low powers 

 this is a very interesting object. The minute struc- 

 ture affords no feature of popular interest. This 

 fungus (which bears the name of Ghcetomium 

 elatwm) is common on old straw, thatch, reeds, 

 matting, &c., resembling small brown tufts of hair, 

 visible to the naked eye. 



Paper much exposed to damp will occasionally 

 develop a similar " bristle-mould,'^ surrounded by 

 a yellowish spot {Ghcetomium, cha/rtwrum, Bhrb.); 

 but it is not so common as the- last. In habit 

 and structure it is very similar (figs. 252, 253). 



In 1838, the Rev. M. J. Berkeley announced the 

 discovery by him of a singular production, for 

 which he was unable to find a fitting location in 

 any genus then estabUshed, and for which he accord- 

 ingly characterized a new one, under the name 

 of Ascotricha. This now species of paper mildew 

 was found by him on some printed paper in a box. 

 It somewhat resembles the other species above 

 alluded to, at a casual glance ; but more minute 

 examination wiU reveal its differences. The author 



