OTHER HYMENOMYCETES 169 



exercise any reproductive function, but merely assist those which 

 do. However, the neuters of Apis mellifica and the non-reproducing 

 myceha in a compound mycehum of Coprinus sterquilinus exhibit 

 marked differences. A neuter bee has a structure strikingly different 

 from that of a queen bee or a drone, which prevents the neuter bee 

 from reproducing itself but admirably fits it for the work that it 

 has to do ; whereas, in the compound mycelium of the Coprinus, 

 the individual mycelia are morphologically indistinguishable. The 

 mycelium which produces a fruit-body does so by virtue of its more 

 favourable position in the substratum and not by virtue of superior 

 reproductive power. The factors, such as light, space, etc., which 

 decide where on the exterior of a dung-ball a fruit-body rudiment 

 may develop into a perfect fruit-body have already been treated of 

 in Part I, Chapter V. 



Social Organisation in Other Hymenomycetes. — Whenever the 

 mycelium of one of the Hymenomycetes is studied in detail in 

 artificial cultures, the hyphal fusions which are formed between 

 adjacent hyphae of the same monosporous mycelium, or between 

 hyphae of different monosporous mycelia, are almost sure to attract 

 attention. Brefeld ^ records great numbers of hyphal fusions as 

 occurring in monosporous mycelia of Coprinus stercorarius and 

 points out that, in this species, even very young mycelia, when 

 scarcely more than germ-tubes, often become united into a single 

 network. Richard and Olga ralck,^ in the account of their study 

 of the germination of the spores of Psalliota campestris, show hyphal 

 fusions in a monosporous mycelium and also several mycelia uniting 

 together to form a single compound network. I, myself, have 

 observed hyphal fusions similar to those just described not only in 

 Coprinus sterquilinus but in many other Coprini, particularly in 

 Coprinus lagopus, and also in Panus stypticus. For Coprinus 

 lagopus, a heterothallic species of which fruit-bodies are shown in 

 Fig. 4S (]). 70) and in Figs. 107, lOS, and 100 {vide, infra), the union 



1 O. Brefeld, Unlcr.'iHrhmujni Lbcr Pihc, Lti|;zig, Heft HI, 1877, pp. 1()-17, 

 Taf. I, Fig. 3. Brefeld also observed anastomoses in the myeelia oiCojninvs lagopus, 

 ('. rphemerus, and C. cphcmeroides {ibid., pp. 1(»3. 110, llS). 



- Riehard and OJua Falck. " tlber die Sporenkeimuny des Cliampiiinons," in 

 Falck's MycoJucjische Untersuchuiicjen viid Berichte, Beiheft I, 1924, Text-figs. 1 

 and 5. 



