254 M. C. COOKE ON BLACK MOULDS. 



granulated. There are intimations that these spores are produced at 

 the tips of the threads, and concatenate. Such features are also 

 possessed by the fungus described by Berkeley and Broome, except 

 that there are clear specific differences in the more distinctly echi- 

 nulate spores, as well as in some other features which need not be 

 enumerated here. Manifestly these moulds do not belong to Hel- 

 minthosporium, but to Heterosporium, a name very characteristic on 

 account of the diversity of their spores. Henceforth then we may 

 regard as British species Heterosporium ornithogali, K.I., on Star of 

 Bethlehem, Heterosporium echinulatum (B. & Br.), on leaves of 

 Lychnis, and Heterosporium variabile, C, on leaves of spinach, 

 from Forden, first described in Grevillea as Helminthosporium 

 variabile, and afterwards on authority of Mr. Berkeley, accepted as 

 a variety of his species, but which differs considerably in habit, as 

 well as in microscopical features. There are probably other species 

 of Helminthosporium, as well as of Cladosporium, which, upon ex- 

 amination, may be found to belong to this genus, whilst the species 

 named by Klotsch Heterosporium maculatum, is only a Cladosporium. 

 These are rather more technical details than I proposed entering 

 upon, but they seem to be essential in order to clear up some doubts? 

 errors, and misconceptions. 



Another of this group of genera consists of the well-known, and 

 widely-distributed genus, Cladosporium. Perhaps one of the most 

 cosmopolitan of Fungi is Cladosporium herbarum, which seems to 

 occur all the world over, and certainly with us it is the commonest 

 of all moulds. As to its relationship with any species of Sphceria, 

 as its conidia, that is a question upon which I do not purpose to 

 enter at all, nor the relationship which any other of the moulds 

 under present consideration bear to other fungi. That is a wide and 

 complex question Avhich would occupy all the time which a paper of 

 this kind can claim at your hands, in order to deal with satisfactorily. 

 We must, therefore, dismiss from our minds for the purposes of this 

 communication all doubts as to the autonomy of the several species. 



Cladosporium occurs on all kinds of vegetable substances during 

 decay. There are flocci, which are often short, septate, coloured, 

 with thin cell-walls, in many instances fasciculate, bearing at their tips 

 chains of spores, or rather one, two, or three sporeS, attached in a 

 chain. These spores are at first without septa, but soon have a 

 septum across the centre ; occasionally there is an additional septum, 

 but in no instance of a veritable Cladosporium does the epispore 



