208 Transactions British Mycological Society. 
continued growing. Their hyphae scarcely showed themselves on 
the surface of the dung. However, after twelve days had passed, 
sclerotia began to develop on the dung in both tubes. These 
sclerotia which were at first white, grew rapidly in size, excreted 
large water drops, and then turned black on their exterior, 
except where they happened to press against the glass. Two ripe 
sclerotia were removed and placed on wet sterilised sand under 
a bell-jar; and there, after a few days, they developed normal 
fruit-bodies which shed vast numbers of spores. Thus for 
Coprinus stercorarius two mycelia of monosporous origin, like 
similar mycelia of C. sterquilinus and C. lagopus, fruited in a 
perfectly normal manner. 
A wild fruit-body of Coprinus stercorarius came up from a 
sclerotium which developed spontaneously on horse-dung in the 
laboratory, and it shed spores which were collected as a spore- 
deposit. Some of the spores were plated out on agar and thus 
a monosporous mycelium was obtained. This mycelium, after 
being transferred to a horse-dung tube, produced a sclerotium, 
and the sclerotium produced a second fruit-body. From this 
second fruit-body four monosporous mycelia were obtained. Of 
these, up to the present, one has produced sclerotia only, one 
sclerotia and several fruit-bodies directly from the dung, and 
two fruit-bodies directly from the dung but no sclerotia. Using 
the same symbols as before, the sequence for a single line may 
be expressed as follows: 
F)—> (S+MM—F)—> (S>MM-—F). 
Thus fruit-bodies of Coprinus stercorarius have been obtained in 
monosporous cultures for two successive generations. 
In Coprinus stercorarius, just as for C. lagopus, clamp- 
connections were found on the following kinds of mycelia: (1) 
several mycelia of monosporous origin, the spores having been 
derived from a wild fruit-body, (2) a mycelium of monosporous 
origin derived from a spore produced by a fruit-body of mono- 
sporous origin, and (3) a compound mycelium of polysporous 
origin derived from spores produced by a fruit-body of mono- 
sporous origin (Plate VI, Fig. 9). We may conclude, therefore, 
just as we did for C. lagopus, that Coprinus stercorarius is 
homothallic. 
Kniep states, without as yet giving the details of his evidence, 
that Coprinus stercorarius is heterothallict. My observations 
which have clearly shown that clamp-connections in C. sterco- 
vayius appear in monosporous mycelia, do not support Kniep’s 
statement. Judged by the clamp-connection tests, C. sterco- 
varius is certainly homothallic. 
* Hans Kniep, Uber morphologische und physiologische Geschlechtsdiffer- 
enzierung, loc. cit. p. 13, foot-note. 
