HYPHOMYCETES. 105 



MUCED'INES. Many of the Fungi belonging to 

 this family are extremely common on decaying vege- 

 table substances, and some are found upon living 

 plants, to which they are very injurious. To the 

 naked eye they usually appear as mouldy or cottony 

 masses, either white, black, or coloured blue, yellow, 

 &c. The spores are attached singly or in rows to 

 branchlets arising from the ends of the filaments, so 

 as to form little heads. 



Bot'rytis parasit'ica (PI. VII. fig. 19) is common 

 upon the flower-stalks of the Shepherd's Purse, form- 

 ing white mealy patches. The fruit-stalks are com- 

 paratively large and thin-walled, the branchlets 

 being slender, mostly curved, and terminated each 

 by a large, spherical, smooth, simple, white spore. 



Botrytis vulgdris is also common on various decay- 

 ing plants. Its filaments are grey, and the branchlets 

 lobe-like ; the spores being minute, spherical, either 

 white or greenish, and placed simply at the tips. 



Botrytis infes'tans is the potato- Fungus. It forms 

 white spots upon the under side of the leaves of the 

 potato-plant, and by some authors is considered to 

 be the cause of the potato-disease. The filaments are 

 branched at the ends, and terminated by single oval 

 spores, which are apiculate at the free end, and con- 

 tain minute little spores or sporidia. 



Oid'ium Tuck'eri is the well-known destructive grape- 

 Fungus. It forms white cottony masses upon the 

 vine and its grapes, the fruit-stalks being short and 

 terminated by one or two end- to- end oblong spores. 

 It appears to be the Coniomycetous form of another 

 Fungus (Erysiphe). 



Trichothecium roseum (PL VII. fig. 33) is found 

 upon rotting sticks; very frequently upon willow- 

 baskets kept in a damp place. It forms little rounded, 

 slightly raised, pinkish spots, less than the size of a 

 pin's head. The branched and septate foot-stalks 

 (figs. 34, 35) are terminated each by a little group of 



