34 RESEARCHES ON FUNGI 



The relation of the fruit-bodies of Psathyrella disseminata with 

 one of the inverted stumps will be made clearer by reference to 

 Figs, 20 and 21. In Fig. 20 is represented semi-diagrammatically a 

 vertical section through the stump and soil. The wood at w was 

 found to be very rotten, its destruction presumably having been 

 caused by the mycelium of the fungus. This rotted wood was white 

 and the mycelium within it colourless. The red mycelial cords and 

 hyphae, to which reference has already been made, originated in 

 crevices of the bark of the stump and stretched, as shown at r, 

 through the interstices of the most superficial layer of the soil to a 

 maximum distance of two feet. Upon this mycelium, and in con- 

 tinuity with it, the numerous fruit-bodies were situated. A small 

 section of the soil with the mycelial network in the crevices is shown 

 in Fig. 21 at A, and fruit-bodies in various stages of development 

 are represented as arising from it. A small piece of a mycelial cord 

 removed from the soil is shown at C with its natural size, and 

 another piece at E highly magnified, while some of the individual 

 hyphae which come off from the outer surface of the cords are 

 represented at F. 



The mycelial cords and the individual hyphae shown in Fig. 21 

 at A, C, E, and F, were all red and, in the damp black soil from 

 which they were removed, much resembled fine roots ; but they 

 anastomosed in all directions, so that the system which they com- 

 posed was retif orm. Their intimate contact with the particles of the 

 soil was reminiscent of that of fine roots clothed with root-hairs. 

 A single hypha, when branching, often produced a branch which ran 

 parallel to, and became adherent to, the mother-hypha. Between 

 a simple mycelial cord made up of two hyphae thus produced 

 (F, c) and the largest cords which were about 0-3 mm. in diameter 

 and consisted of some hundreds of hyphae (E) there were all transi- 

 tional stages. The walls of the hyphae were thick (F) and it was 

 owing to this fact that the mycelial cords, although so slender, were 

 yet found to be tough and resistant to mechanical tearing. 



So far as the stumps represented in Figs. 18 and 20 are con- 

 cerned, the fruit-bodies were free ; for, as we have seen, they arose 

 upon the red mycelium which penetrated through the soil. With 

 other stumps, some of the fruit-bodies were found to be situated 



