204 Transactions British M: ‘ycological Society. 
at the end of the third month also fruited; and so on for five 
successive generations. If we let S =a single spore, MM =a 
monosporous mycelium, and F = a fruit-body, then the sequence 
just described may be set forth as follows: 
F)—> (S+MM +F)—> (S+MM~>F)—> 
(S+>MM-~F)—> (S~MM—F)—> (S+MM—F). 
Thus fruit-bodies of Coprinus sterquilinus were obtained in 
monosporous cultures for five successive generations*. The 
first fruit-body of the fifth generation is shown in Plate VII, 
Fig. I. 
Experiments with twenty-one monosporous cultures of Co- 
prinus sterquilinus has taught me that this fungus fruits from 
mycelia of monosporous origin with remarkable certainty and 
perfection. In a monosporous culture of this species one can 
rely upon seeing fruit-body rudiments appear at the surface of 
the dung after about a fortnight from the sowing of the spores, 
and one can also rely upon obtaining mature fruit-bodies, 
producing vast numbers of spores, from some of the same 
rudiments at the end of about a month from the time of the 
sowing of the spores. All the monosporous cultures of Coprinus 
sterquilinus, therefore, behave in exactly the same manner so 
far as fruiting is concerned. 
We may now ask: is Coprinus sterquilinus homothallic or 
heterothallic? Accepting Kniep’s. view that the production of 
fruit-bodies on a monosporous mycelium is no proof that the 
species is homothallic, it is therefore necessary for us to answer 
our question by the criterion of clamp-connections. I found that 
all the mycelia of monosporous origin which I studied after the 
first few days of their development, even those of the fifth 
successive generation, exhibited clamp-connections with great 
regularity on all the stout hyphae radiating from the centres of 
growth (Plate VI, Figs. 3 and 4). It seems to me, therefore, that 
there can be no doubt that Coprinus sterquilinus is a homothallic 
species. 
Polysporous mycelia arising from the union of the mycelia, 
coming from several spores sown in a clump, were isolated from 
agar plates and grown side by side with monosporous mycelia 
as controls. No difference between the polysporous mycelia and 
the monosporous ones could be observed as regards rapidity of 
appearance of mycelial growth, presence of clamp-connections, 
rapidity of fruiting, or in the perfection of the fruit-bodies 
produced. The polysporous cultures fruited sometimes a day or 
* Since this was written, fruit-bodies have been obtained from a sixth 
successive monosporous culture. 
