260 M. C. COOKE ON BLACK MOULDS. 



together, and the undoubted influence which one exerts upon the 

 other, it is far more philosophical to be sceptical, than to accept 

 assumptions as fact. If it cannot be shown that the presumed 

 conidia of any one of the Dematiei affect the life history of any one 

 species of Sphceria, or that there is any closer functional relationship 

 than mere association, it is only raising a monument to our own 

 ignorance, to apply to them the name of Conidia, when we do not 

 know ourselves what we mean by the term so recklessly employed. 



There is a small but very important group of the Dematiei, in 

 which the spores, instead of being produced singly, or in chains, at 

 the tips of the threads, or their branches, or from their sides, are 

 generated in clusters forming, more or less, globose heads, either at 

 the apices of the threads or their branches. These moulds are re- 

 presented by two or three genera in Britain, of which Sporocybe is 

 one. 



Some difference of opinion seems to prevail between mycologists 

 as to the recognised limits of this genus, which must be noticed 

 here, lest the conclusion be arrived at that I am ignorant of the fact. 

 Sporocybe, as accepted by the Rev. M. J. Berkeley* and myself, f has 

 simple threads, terminated by a globose head of spores. Others con- 

 tend that the stem may be either simple, or compacted of several 

 threads together into a common stem. This is such a manifest and 

 distinct difference, that I am surprised to find continental mycolo- 

 gists, always mad for new genera, supporting the anomaly for a 

 single day. To have confounded Sporocybe with Periconia, and 

 mixed the two together, rests, however, on their responsibility and 

 not on ours, although, undoubtedly, when first established it in- 

 cluded the two forms.! 



During the winter months almost any small portion of the stem 

 of herbaceous plants, such as the nettle, found lying in a damp 

 situation, will be seen to be covered with delicate black hairs, almost 

 invisible to the naked eye, but visible under an ordinary pocket 

 lens. This is Sporocybe byssoides, so common and so widely diffused 

 that it can scarcely escape notice. In this mould the threads are 

 rigid, erect, and without branches, the tips are thickened into ahead 

 and upon this are borne the globose dark coloured spores, which 



* Berkeley's Outlines of Fungology, p. 343. 



t Cooke's Handbook of British Fungi, p. 566. 



X Fries (1825), Sys. Orb. Vet , p. 170 ; Corda Icones, iv., p. 29, " Stipes 

 simplex erectus, floccif ormis, septatas ;" also Corda Ic, v., p 15 Berk 

 Outl., p. 343. Cooke. Hdbk., p. 566. 



