113 



rather singular that the species has not been yet recorded as a British 

 production. I have the high authority of the Rev. M.J. Berkeley for 

 this fact, who informs me that our mould is the Botrytis umbellata* 

 of De Candolle. 



" Botrytis umbellata. — On a flat and smooth leaf, the decumbent 

 filaments of this mould form a cobweb-like mycelium, but on leaves 

 with an uneven surface, and on the stalks of herbs, the mycelium is 

 so filamentous and thin as to be scarcely perceptible ; while the erect 

 filaments are so numerous as to render the surface downy or hirsute. 

 The decumbent filaments are also slenderer than the others, but there 

 is no difference in their structure ; they are smooth hyaline membra- 

 nous tubes, jointed at distant intervals, the joints alternately swollen 

 and constricted, but not regularly so, and when moistened with 

 water, the whole tube becomes swollen, tense, and cylindrical. The 

 erect filaments are two lines in height, of a grey or cinereous colour, 

 with a hoary sporuliferous head ; they are sparingly and irregularly 

 branched, and at the top four or five short divergent branchlets form 

 a sort of imperfect umbel, collecting, as it were, the sporules into a 

 round heap or summit. The main branches are either divergent or 

 dichotomous ; and many of the filaments are quite simple. The 

 sporules are ovate or elliptical, often marked with a septum, some- 

 times transversely, and in others in a longitudinal direction ; and 

 this septum disappears when the sporules are moistened. The num- 

 ber of sporules is incalculable ; they fall from the head, and are found 

 adherent to every fibre of the plant; and when this is shaken, they 

 fly abroad in a little cloud. 



" My friend Mr. Bowerbank examined this mould with the micro- 

 scope. When highly magnified, many of the main filaments exhibited 

 slight protuberances, which were supposed to be incipient branches ; 

 these were sometimes opposed to each other, and sometimes they 

 were not quite in opposition. The sporules varied considerably in 

 size, and were ovate or elliptical. Placed in water between glasses, 

 after a lapse of two days it was found that most of the sporules had 

 germinated, each emitting a single filament, which was sparingly and 

 irregularly branched, and contained some very minute granules. 



"January 6th, 1847." 



'< * Lam. et De Caud. Fl. Frang. ii. 71. Duby, Bot. Gall. ii. 921." 



