212 Transactions British Mycological Society. 
both monosporous and polysporous mycelia; and, for the 
present, one cannot say whether or not the fruiting power of 
the mycelium is affected by its monosporous or polysporous 
mode of origin. 
Polysporous mycelia of Coprinus comatus develop an abun- 
dance of clamp-connections but no clamp-connections could be 
observed in two monosporous mycelia. These two monosporous 
mycelia were cultivated for 90 days in dung tubes. Then 
portions of the mycelia were removed from the fubes and placed 
on agar plates. The mycelia grew well on the plates, but none 
of their hyphae developed clamp-connections. On the other 
hand, a mycelium derived from a stipe and placed on an agar 
plate under the same conditions as the monosporous mycelia, 
developed an abundance of clamp-connections. These observa- 
tions indicate that Coprinus comatus is probably a heterothallic 
species. However, before this conclusion can be accepted as 
having been proved, some further experiments upon the mycelia, 
especially crossings, ought to be undertaken. 
IX. SUMMARY OF DATA. 
The following table summarises data for the nine species of 
Coprinus treated of in the foregoing pages. 
Summary of Data for Species of Coprinus 
Presence or absence of 
Number —clamp-connections 
of mono- 
sporous inmono- inpoly- Presence Homothallic 
cultures sporous sporous or absence or 
Species made mycelia mycelia of oidia heterothallic 
C. sterquilinus 21 + o ~ Homothallic 
C. lagopus 12 + + + 55 
C. steycovarius 6 a + - 5 
C. niveus 5 + + + > 
C. ephemerus 2 ? + + Not determined 
C. curtus 6 - - + us 
C. stellatus i - - + = 
C. cordisporus I - = 45 ” 
C. comatus 2 - ct ? Heterothallic 
Total!” 4: 56 
X. DISCUSSION. 
From the facts communicated in the foregoing pages, there 
seems to be no doubt that Coprinus sterquilinus, C. lagopus, 
C. stercorarius, and C. niveus are all homothallic; while, on the 
other hand, C. comatus appears to be heterothallic. Mlle 
Bensaude found that her C. fimetarius is heterothallic. Hence 
it appears that, in the genus Coprinus, some species are homo- 
thallic and others heterothallic. 
