l62 



RESEARCHES ON FUNGI 



Fig. 91. — Social organisation oi''C'oprinus sterquilimis, a homothallic Hymeno- 

 mycete. Diagrams of a vertical section througli a horse-dung ball containing 

 numerous spores (24 shown) whicli germinate and produce mycelia which imite 

 with one another and collectively exhaust themselves in promoting the develop- 

 ment of a single fruit-body which has originated on one of the mycelia. A, the 

 dung-ball, just dropped in a pasture ; 24 spores are seen scattered within it at 

 fairly uniform intervals. B, about 24 hours later ; all the spores have germin- 

 ated and the young mycelia are rapidly invading the adjacent substratum. 

 C, a few days later ; the mycelia are coming into contact with one another and 

 are passing from the haploid to the diploid phase ; clamp-connexions are 

 begirming to appear here and there, e.g. on the mycelitun a ; the mycelia are 

 about to unite with one another to form a compound three-dimensional net- 

 work ; the hypha b of the mycelium a is destined to produce a fruit-body 

 rudiment which will grow into a perfect fruit-body. D, about a month after 

 the dtmg-ball was deposited ; the twenty-four monosporous mycelia in view, 

 now in the diploid phase, have imited to form a single, compound, closely- 

 meshed, three-dimensional network. The fruit-body, which originated solely 

 from the hypha b of the mycelium a and therefore contains nuclei derived from 

 the mycelium a only, is developing at the expense not only of the mycelium a 

 but also of all the other mycelia (23 others shown) which are yielding up their 

 contents to it and are exhausting themselves in so doing. Not one of the 

 simple monosporous mj'celia by itself was large enough to produce a fruit-body; 



