BIOLOGY OF COLLYBIA VELUTIPES. 153 
abundant granular contents and high refractive power also 
serve to make it more visible (PI. 2. fig. 4). 
In transverse sections of the stipes the hyphæ of this system 
appear as a deeply stained ring near its outer margin. These 
hyphs push their way among the parallel hyphæ of the stipes, 
occasionally giviug off blindly ending branches, which run either 
in the original direction or in the opposite one. From the 
stipes they run into the pileus, where they spread out over its 
lower surface and send down branches into the trama of the 
gills to form a layer immediately below the subhymenium. 
Here they either end in slight dilatations, or pass into the 
hymenium and end between the barren cella (Pl.2.fig.5). Very 
few branches are present in the upper portions of the pileus. 
The system is evidently identical with the “conducting 
system” described by Istvanfli* in the closely allied genus 
Mycena among others. 
The structure of the cortex is unusually complex. The 
hyphæ, which are considerably smaller than those of the medulla, 
and arranged parallel to the surface of the pileus instead of 
being woven together in all directions, turn outwards and give 
rise to three distinct forms of hairs (PI. 2. fig. 6). The most 
conspicuous are large, simple, and spindle-shaped, with granular 
contents coloured a yellowish-brown (a in fig. 6). Among these 
are clusters of three or four smaller hairs, which arise as 
branches from the apex of a hypha; they are often constricted 
at intervals so as to have a beaded appearance (b). Standing 
out above these two forms are long, fine, much-branched hairs, 
which often entangle basidiospores among them, and so give 
rise to the “white-washed’” appearance of the sporophores 
described by Sowerby (c) It seemed probable that the 
sliminess of the upper surface might be due to the formation of 
mucilage by these hairs, either as a secretion, or by the muci- 
laginous degeneration of their walls. Sections were accordingly 
stained with methylene-blue and other mucilage stains, but no 
indications of its presence were obtained, nor were the walls 
found to be swollen. It is possible, then, that the sliminess is 
due to the quantity of water held by capillarity among these 
slender hairs; but whether any of the forms are specialized for 
the purpose of transpiring water could not be determined. 
* Istvanffi, Bot. Centr. vol. xxix. 1887, p. 373; Pringsh. Jahrb. 1896, p. 391. 
