Miscellaneous. 467 



nearest to that of the large extinct Edentata, the Mylodons ; but tiie 

 structure of the symphysial portion is unlike that of any other 

 animal. Dr. Mantell will shortly present a memoir on this most 

 interesting discovery to the Royal Society, in whose Transactions 

 his first memoir on the Teeth of the Iguanodon was published in 

 1825. The lower jaw, containing teeth, was discovered by Captain 

 Bickenden, the upper by Dr. Mantell : both are from the same loca- 

 lity in Tilgate Forest. 



Description of a new British Mould. By George Johnston, M.D. &c. 



I am willing to believe, with my Lord Bacon, that Mould " is 

 something between putrescence and a plant." It settles a much- 

 mooted point as well as any other theory has yet done. Organic 

 substance, in a state of decay, is Mould's fruitful matrix, — life from 

 death, — the ever-yearning change from a worse to a better condition ; 

 for life, even in this its lowest state, is better certainly than sad 

 corruption. And how beautiful are many Moulds, when, with the 

 microscope, we discover Nature's handicraft in them to the eye of 

 sense ! We can scarcely but believe that they have a sort of enjoy- 

 ment in their life, and in the evolution of their symmetrical figures. 

 One sort is now vigorous and abundant on some plants in my little 

 " Green-house," where it is as noxious as the Green-fly, or Aphis ; 

 and it is 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 Bo- 

 trytis umbellata* of DeCandolle. 



Botrytis umbellata. On a flat and smooth leaf, the decumbent fila- 

 ments 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 

 membranous 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 gray or cinereous 

 colour, with a hoary sporuliferous head ; they are sparingly and ir- 

 regularly branched, and at the top four or five short divergent branch- 

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

 into a round heap or summit. The main branches are either diver- 

 gent or dichotomous ; and many of the filaments are quite simple. 

 The sporules are ovate or elliptical, often marked witli a septum, 

 sometimes transversely, and in others in a longitudinal direction ; 

 and this septum disappears when the sporules are moistened. The 

 number 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. 



* Lam. et DeCand, Fl. Fran9. ii. 71. Dubv, Bof. Gall. ii. f)21. 



31* 



