176 



RESEARCHES ON FUNGI 



conidia of each ball were held together by a drop of liquid. At the 

 stage shown in Fig. 100, the peripheral parts of the compound 



Fig. 100 — Social organisation in Trichoderma lignorum made 

 possible by non-sexual hyphal fusions between monosporous 

 mycelia. Seven spores (conidia), s s, sown in a hanging drop 

 of malt-agar, have produced seven monosporous mycelia which 

 have fused together to form one compound mycelium. Only 

 one of the monosporous mycelia, a, has produced a conidio- 

 phore, b, and balls of conidia, c. The other six mycelia are 

 remaining sterile and are giving up their contents to a. The 

 peripheral parts of the compound mycelium, suchasd, e,/, 

 and g, have already lost most of their protoplasmic contents 

 (for full mycelia cf. Fig. 99). The compound mycelium is en- 

 tirely submerged in the malt-agar, the conidiophores and 

 conidia are sub-aerial. The conidia in each ball are held 

 together by a drop of liquid. Drawn by A. H. R. Buller 

 and Ruth Macrae. Magnification, 466. 



mycelium, {d, e,f, g), have already become emptied of most of their 

 protoplasmic contents. From an inspection of Fig. 100 it is obvious 



