210 Transactions British Mycological Society. 
The result of the experiment was truly remarkable, for the 
three mixed cultures all fruited vigorously and their fruit-bodies 
shed spores 24-28 days after the sub-cultures had been made; 
whilst, at the end of this time, the unmixed cultures showed not 
even a single fruit-body rudiment. The culture (1) A by itself, 
showed its first rudiments after about 29 days, but the fruit- 
body did not expand until the 33rd day. The other unmixed 
cultures (2) and (3), B by itself and C by itself, on the 33rd day 
had not yet shown any rudiments whatever. 
From the series of experiments just described, it would seem 
that Coprinus miveus, although homothallic, fruits much more 
vigorously in mixed cultures than in monosporous ones. This 
conclusion is an important one, for it seems to indicate that in 
a homothallic species when two mycelia in the diploid condition 
are allowed to unite, the compound mycelium resulting may 
fruit more vigorously than either of its components when sepa- 
rated. Is it possible that, when two diploid mycelia unite, the 
dicaryons may become rearranged so as to allow of sexual 
crossing? If so, we might conclude that crossed compound 
mycelia in Coprinus niveus fruit more vigorously than uncrossed 
or selfed mycelia, and we might appeal for an analogy to the 
results obtained by Charles Darwin in his experimental studies 
of cross-fertilisation and self-fertilisation in Flowering Plants. 
I regret that, up to the time of writing, I have not been able to 
repeat and extend the experiments which have just been 
described. 
In Coprinus sterquilinus and C. stercorarius which, like 
C. miveus, are homothallic, a compound mycelium arising from 
many spores sown together did not appear to fruit any more 
vigorously or any sooner than monosporous mycelia grown 
under similar conditions. Hence we may conclude that, although 
in Coprinus niveus the mixing of the mycelia appears to increase 
the capacity for fruiting, yet this does not hold true for C. ster- 
quilinus and C. stercorarius. 
VII. OTHER SMALLER SPECIES. 
Of Coprinus ephemerus Fr. three cultures were made, two 
monosporous and one polysporous, in dung tubes. All the three 
cultures produced fruit-body rudiments, but only the poly- 
sporous culture produced perfect fruit-bodies. Clamp-connec- 
tions were found in the polysporous mycelium (PI. VI, Fig. 12) 
but were not searched for in the monosporous mycelia. 
Coprinus curtus Kalchb., C. stellatus Buller (a new and as yet 
undescribed species of the ephemerus group) and C. cordisporus 
Gibbs (a Canadian form of the species) were also investigated 
