94 RESEARCHES ON FUNGI 



conically pointed or obtusely convex below and, at the same time, 

 thicker. The result is that the base of the stipe comes to press 

 against the surrounding leaf -mould or soil which returns the pressure 

 and, in so doing, gives the stipe mechanical support. Furthermore, 

 the outer hyphae of the base of the stipe penetrate the substratum 

 wherever contact has been made and anchor the stipe to the leaf- 

 mould, etc. Thus the attachment of the base of the stipe to the 

 substratum becomes so extensive and so firm that the fruit-body, 

 when full-grown, is supported by the stipe in one fixed position 

 (c/. for Psalliota campestris Vol. I, Fig. 76, p. 218 and for Coprinus 

 picaceus Vol. Ill, Fig. 129, p. 297). That terrestrial fruit-bodies 

 take a strong hold on their substratum is proved by the fact that, 

 when one pulls one of them up, one invariably observes leaves, 

 soil particles, or cinders, etc., clinging to the base of the stipe. 



In Collybia radicata the fruit-body arises as a tiny rudiment on 

 the surface of a buried root of a Beech, Oak, or some other tree. 

 By intercalary growth at the base of the stipe there is formed a 

 rod-like pseudorhiza or " rooting base " which gradually pushes 

 the rudimentary pileus and rudimentary stipe-shaft up to the 

 surface of the ground, where they expand and form a large aerial 

 fruit-body. The pseudorhiza, as it grows in length and approaches 

 the surface of the ground, gradually thickens and becomes mechani- 

 cally stronger. Finally, its thickest part is continuous with the 

 base of the aerial stipe-shaft. The fully-developed pseudorhiza is 

 held fast in a vertical position by pressure from the surrounding 

 soil and, in turn, the pseudorhiza supports the aerial stipe-shaft 

 and pileus. Thus the fixation of a fruit-body of Collybia radicata 

 by its pseudorhiza is comparable with the fixation of a herbaceous 

 flowering plant, such as a Lupin or a Dandelion, by its tap-root. 

 In respect to the manner in which their fruit-bodies are fixed in 

 the ground, the other agarics with stipes ending in a " rooting base," 

 e.g. Collybia longipes, Pholiota radicosa, and Coprinus rrmcrorhizus, 

 resemble Collybia radicata. 



Coprinus sterquilinus. — Coprinus sterquilinus produces its large 

 fruit-bodies (Figs. 54, 55, and 56) in pastures on horse dung. This 

 substratum is made up of more or less ball-like masses irregularly 

 heaped together. One may therefore ask : by what means do the 



