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Note on Chaetomium bostrychoides, Zopf. 



By George Massee, F.L.S. 



{Bead May \Uh, 1902.) 



This beautiful little fungus was discovered in Germany several 

 years ago, growing on rabbit dung ; last year it occurred in 

 England on the same substratum, and quite recently it has been 

 received from Calcutta, where it occurred on the dung of a fruit- 

 eating bird. The genus Chaetomiurti belongs to the Sphaeriaceae, 

 or ascigerous fungi, and, as the name denotes, the component 

 species are ornamented with external hairs, which are often much 

 branched or curled in various apparently fantastic ways ; but 

 when these minute organisms are carefully studied, it is seen that 

 the branching or twisting of the hairs serve some important func- 

 tion in the economy of the species. In the fungus under 

 consideration the perithecium, or outer protective wall enclosing 

 the spores, is egg-shaped, about 1 mm. high, and in the early stage 

 is everywhere covered with short, dark-coloured, bristle-like rigid 

 hairs. During this stage the spores are maturing, and are 

 eventually expelled through a small opening at the tip of the 

 perithecium as a compact black mass, bound together by a 

 mucilaginous substance. 



Now, simultaneous with this expulsion of the mass of mature 

 spores, a specialised set of hairs grow up round the opening at the 

 tip of the perithecium. Each hair is straight and rigid for 

 some distance at its base, but the apical portion is twisted into a 

 dense corkscrew-like coil, one portion of the coil turning to the 

 left, the other portion to the right, the two coils being separated 

 by a short straight portion, as in the tendrils of the vine. 



