M. C. COOKE ON BLACK MOULDS. 259 



the threads are stouter and branched, and the spores are larger, or at 

 least form a larger coil. 



A curious circumstance may be mentioned in connection with 

 Helicoma, to which Mr. C. B. Plowright, of King's Lynn, has 

 directed my attention.. He has found growing upon sawdust a 

 Heliconia which differs somewhat from //. Mvlleri, in having rather 

 larger spores, and in the threads being accompanied by other, appar- 

 ently barren threads, which are more slender, and with longer joints. 

 In company with this Helicoma, and intimately associated with it, he 

 found a species of Sphceria with sporidia nearly of the same size and 

 form as those of the Helicoma, but straight, and not helicoid. It is 

 a most interesting Sphceria, and seems to be quite distinct from any 

 species previously described. What are the relationships which 

 subsist between these two very widely distinct fungi is a very 

 natural question ? Some there are who would cut the gordian knot 

 at once, and declare upon circumstantial evidence that the Helicoma 

 is but the conidia of the Sphceria. It is true that circumstances 

 seem to favour such an assumption, but, after all, more definite and 

 decided evidence must be afforded before we can accept such an 

 assumption as an established fact. Too many such assumptions are 

 already passing current as facts, and what we require is investigators 

 who will endeavour to trace out patiently the relationships which 

 subsist between these associated forms. If the black mould should 

 be termed the conidia, then the question arises, what is the role of 

 these conidia ? What functious do they perform in relation to the 

 Sj)ha>ria, with which they are associated ? Are they a depraved 

 condition, or are they simply a second form of fruit ? If the conidia 

 spores germinate under favourable conditions, will they ever produce 

 a Sph&ria, or, on the other hand, will the Sphceria degenerate into 

 a black mould ? Calling them by a name, whether " conidia," or 

 " stylospores," is only removing the difficulty a step further, but not 

 solving it. It might prove stronger evidence if the same black mould 

 always accompanied the same Sphceria, but such is not the case. 

 Monotospora will at one time be found with one Sphwria, at another 

 time with another, or even with an Hysterium. A species of 

 Helminthosporium will accompany one Sphceria to-day and another 

 to-morrow. In fact, we possess numerous instances of this idiosyn- 

 crasy which debars me from accepting as fact deductions from mere 

 association. After all, the circumstance of their occurring together 

 may be accidental, and until we know the reason why they are 



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