488 BOTANICAL GAZETTE [JUNE 
intertwining hyphae running parallel to the stroma and taking a 
very dark stain, a space occupied by loose hyphae with dense 
protoplasmic contents, and a bounding surface of close hyphae 
staining black and doubtless containing the remnants of 
conidiophores. 
In the central region three types of hyphae are distinguishable. 
The most conspicuous of these (fig. 2) is the one of large long cells 
Fic. 1.—Longitudinal section showing borders of the four zones of stroma and the 
additional markings seen in compact layer of stroma; perithecia visible in fruiting 
zone; X26. 
staining brown, between which are small hyphae with dense proto- 
plasm, and still smaller ones not staining so densely. These are 
apparently differentiated from the time of emerging from the sub- 
stratum into stroma-forming hyphae, into hyphae which form the 
perithecium, and into those which form the conidiophores and 
superficial layers. The supporting structure is formed entirely 
by the largest filaments by means of various devices for interlocking 
the whole mass and giving to the stroma sufficient firmness, and 
the same devices are used also in the zone above this. One of the 
