Mutinies caninus (Hints.), Fr . 361 
real course of these crowded hyphae in ordinary preparations. 
Their real courses and arrangement in the region in question 
have, however, been carefully traced in Figs. 9 and 11. 
Hyphae may be seen (Fig. 11) passing through the light 
areas c , c and showing in their different portions the variations 
in intensity of stain characteristic of the adjacent tissue. 
I have traced a hypha from one light area through the 
darker partition-wall into the next light area. The points 
marked c, c in the figure are not the only ones at which 
crossing of interwoven hyphae occurs, but these marked 
points are places in which further advancing differentiation 
ceases, and in which a formation of gelatinous substance sets 
in. Into these lightly staining areas, channels of a similar 
nature may lead from the outer surface of the stipe, and 
thus bring the intermediate tissue A into intimate communi- 
cation with a much greater surface of the pseudoparenchyma 
of the wall (Fig. 14). 
I have stated that the hyphae of the dark partition-walls 
may extend into, or may issue from, the areas c , c. They 
may arise directly from the intermediate tissue A and be 
traced for considerable distances in the dark walls, crossing 
and becoming intertangled with the other hyphae of those 
walls. In these darker portions between the light areas c, c , 
and between these areas and the central column R on the one 
side, and the tissue A on the other, rapid growth and further 
differentiation into pseudoparenchyma occurs in later stages. 
The inflations of the hyphae become greater, and short 
branches are formed. The development of pseudoparen- 
chyma is most active along the surfaces where the partition- 
walls are in contact with the gelatinous tissue of the future 
chambers c , c, with that of the column R, or with the inter- 
mediate tissue A. As a result of such growth, the partition- 
walls become more and more compact along their surfaces 
and more open in structure further in (Figs. 14 and 15). 
Hyphal knots . — Ed. Fischer 1 accounts for the wall of the 
1 L. c., 1887, pp. 17 and 18. 
B b 2 
