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TRANSACTIONS OF SECTION K. 715 
4. Conditions necessary for the Germination of the Spores of Coprinus 
sterquilinus, Fr. By M. L. Baven. 
Many workers have experienced a difficulty in germinating the spores of 
various species of coprophilous Ascomycetes and Basidiomycetes, in some cases 
it being found impossible to germinate them at all in nutrient solutions. The 
same difficulty had to be contended with in the case of Coprinus sterquilinus 
Fr., growing on horse-dung. Attempts were made to germinate the spores in 
various solutions of different strengths, acidity, &c., for several weeks without 
success. Eventually vigorous germination occurred in one particular solution, 
but it was found, on staining, that numerous bacteria were present. Hanging- 
drop cultures of the spores in media with and without the bacteria were there- 
fore made, and in every case it was found that the spores germinated at once 
in the cultures with bacteria, but never at all in those without. This led to 
the conclusion that in some way the bacteria are necessary for the germination 
of the spores of Coprinus sterquilinus Fr. The connection between the bacteria 
and the spores seems to continue for some time after the commencement of 
germination, since the bacteria completely cover the mycelium at certain points, 
particularly where branching occurs. In exactly what way the bacteria are of 
benefit to the spores it is not possible to say, but the following suggestions are 
made. The bacteria may produce certain substances which react on the spores 
in such a way as to soften the wall and thereby make germination possible. 
Schmidt found that certain chemical reagents were necessary for germination 
at temperatures above 40° C. It is not unlikely that the bacteria produce the 
same effect as the reagents, which may even be a product of the bacteria them- 
selves. On the other. hand, the bacteria may remove any by-products which 
happen to be produced by the fungus, germination being impossible while such 
are present. Since various bacteria are always present in the alimentary canal 
of animals, it is quite feasible that there should be some connection between 
them and the spores, and that the two should aid one another. 
5. The Organisation of the Hymenium in the Genus Coprinus, 
By Professor A. H. Recinatp BuLirr. 
1. Most species of Coprinus have four sports on each basidium, but in 
Coprinus bisporiga Buller (as yet undescribed) the basidia usually have two 
spores each, and but rarely one. No three- or four-spored basidia have been 
observed in this species. In (. narcoticus most of the basidia are normally 
trisporigous, but a few occasional ones are quadrisporigous. Coprinus 
narcoticus is the only trisporigous Hymenomycete known to the author. 
2. In Coprinus (neglecting the cystidia which are present in some species 
and absent in others), the hymenium consists of fertile basidia and sterile 
paraphyses. The latter are useful as spacial agents, in thaf they prevent the 
spores on adjacent simultaneously maturing basidia from touching one another. 
3. In most species of Coprinus the basidia are dimorphic. Long, obviously 
protuberant, basidia and short, practically non-protuberant, basidia are inter- 
spersed among one another, so as to form a mosaic-work which is of such a 
kind that the spores of the long basidia are further from the surface of the 
hymenium than the spores of the short basidia, and so that they frequently 
overlap the latter without touching them. The dimorphism of the basidia permits 
of a closer packing of the basidia on the hymenium than would otherwise be 
possible. Hymenial space is thus economised for spore production. In the 
zone of spore discharge, which proceeds upwards on each gill, the long basidia 
discharge their spores a short time before the immediately adjacent short 
basidia. The spores of the short basidia, at the time when they are shot out 
into the interlamellar spaces, are thus prevented from colliding with the spores 
of the longer basidia. In Coprinus micaceus the basidia are quadrimorphic. 
4. The dimorphism of the basidia in the genus Coprinus was discovered by 
the author after the publication of his ‘ Researches on Fungi’ in 1909. A short 
account of the phenomenon was given in the Transactions of the British Myco- 
