1922] LUPO—HYPOXYLON 487 
states that paraphyses arise by an increased growth from the cells 
of the inner perithecial wall. The nuclear program, although not 
clear, is thought to involve an increase in the number of nuclei 
from the first uninucleate Woronin hyphae, and probably also further 
division in the ascogenous hyphae. From the comparative size 
of the nuclei he inferred fusion in the ascus, and this was the only 
fusion occurring in the life history. 
Material and methods 
The material used was collected in September from dead beech 
bark at Sullivan, Ohio, by Professor CHAMBERLAIN, who noticed 
that it seemed soft when all the other stromata around it were 
characteristically hard and mature. Specimens were sent to Mrs. 
FLorA PATTERSON, mycologist at the Bureau of Plant Industry in 
Washington, and she identified the form as Hypoxylon coccineum. 
It was fixed in chromoacetic acid and stained in haemotoxylin. 
Some of the material, which had not been satisfactory in safranin, 
was destained and then run into haemotoxylin; and some of the 
very young material was counterstained in gold orange. Both of 
these latter methods gave good results, because they differentiated 
the fungus cellulose and outlined the hyphae sharply, yet left the 
nuclei clear black and sharply marked. The sections were cut 2, 
3, 4, 5, 8, and tow thick, the younger stages being cut very thin. 
Whether or not the late fall development of this stroma is usual is 
not known to the writer. 
Description of stroma 
In longitudinal section (fig. 1) the stroma of Hypoxylon shows a 
differentiation into four distinct regions that can be seen in thi 
sections even with the naked eye. These are (1) an innermost 
central region, round in shape, which under the microscope is 
marked by a loose arrangement of hyphae emerging from the sub- 
stratum; (2) a compacted zone above this of large, parallel, mostly 
empty hyphae that form a dome over the central region and up the 
main body of the stroma; (3) the perithecial layer of loosely woven 
hyphae with much interhyphal space and perithecia scattered 
throughout the region; and (4) the superficial layer which is 
further differentiated into a line marking off the fruiting zone by 
