COPRINUS STERQUILINUS 



95 



fruit-bodies of G. sterquilinus become fixed in the dung ? An 

 attempt to answer this question will be made in what follows. 

 The enquiry was prompted in the first instance by the discovery 

 that, in artificial 

 horse -dung cultures 

 well exposed to the 

 light, the fruit-bodies 

 were never attached 

 to the tops of the 

 dung-balls, but 

 always to their under 

 sides in dark crevices 

 at or near the bottom 

 of the crystallising 

 dish. The various 

 factors which are 

 concerned with the 

 fixation of C. sterqui- 

 linus fruit-bodies in 

 their position in the 

 substratum will first 

 be considered separ- 

 ately and in detail, 

 and then , in a descrip - 

 tion of the fixation 

 process, an attempt 

 will be made to 

 correlate them. 



The Mycelium at 

 the Surface of its 

 Substratum, — The 

 mycelium of Coprinus 

 sterquilinus at the surface of its horse-dung substratum has various 

 functions to perform, one of which is to aid in the fixation of 

 the fruit-body. To substantiate this statement, it is necessary to 

 describe and discuss the development of the mycelium as observed 

 in the laboratory. 



Fig. 54. — Coprinus sterquilinus. A young fruit-body 

 coming up on a horse-dung ball in a laboratory 

 dung culture. It originated in a dark crevice 

 between three dung-balls, two of which have been 

 removed. Note the mycelium growing over the 

 surface of the dung-ball and the mycelial strands 

 which assist in attaching the fruit-body to its 

 substratum. The young pileus was soon pushed 

 up into the light. Hence the elongation of the 

 stipe-base was soon inhibited by the light and is 

 relatively short. Natural size. 



