CRYPTOGAMI A FUNG I. 141 



In July and August, the upper surface of the leaves of the 

 coltsfoot are often marked with large irregular spots of a 

 reddish-brown colour, mapped with black excavated lines, 

 which are irregularly branched and dilated at intervals. 

 The spots are even with the surface, a discoloration ra- 

 ther than a disease ; but the lines have extended into the 

 substance of the leaf, and are apparently of a parasitic na- 

 ture. They are too regular in their appearance, and too 

 curiously ramified, to be produced by mere decay or mor- 

 tification ; nor are they the work of insects, but as I can- 

 not discover any decided traces of organization, I would 

 not raise the thing to the rank of a vegetable, nor give it 



73. CEUTHOSPORA. 



1 . C. phacidioides, subcircular, plane, or slightly convex, glossy 

 black, smooth, the apex bursting at length by 3-5 short pale seg- 

 ments ; interior brown. G REV. Crypt. Fl. t. 253. Phascidium 

 multivalve, MOUG. and NEST., No. 560. Sphceria bifrons, Sow. 

 Fung. t. 316. Cryptospharia bifrons, GREV. FL Edin. 361. 



Hab. On leaves of the holly, the spots visible on both 

 sides at opposite points. 



74. ERYSIPHE. 



OBS. The Erysiphe grow upon living leaves. They form dif- 

 fused pulverulent or cobweb-like spots on the surface by a tissue 

 of fine appressed filaments, amid which a careful eye discovers 

 minute sessile globules scattered in profusion. The filaments are 

 of two kinds: the one, termed by Dr GREVILLE the radicular, 

 are short, rigid, generally of a darker colour, and perhaps organi- 

 cally attached to the globules ; the other are longer, white, and 

 interwoven, and because thay are produced previous to the ap- 

 pearance of the globules, are named the primary. The globules 

 themselves are always at first of a yellowish-colour, becoming 

 brown and ultimately black. They are filled with oval grains, 

 which appear to be capsules, and each of which is said by DE- 

 CANDOLLE to contain two seeds, but the number is frequently 

 greater. 



1. E. communis, base effused, areneous, whitish ; radicular fila- 

 ments simple, white, affixed to the base ; globules spherical, scat- 



