16 NORTH AMERICAN SORDARIACEAE 
green stage. While the test of maturity adopted here has been 
„the usual one of color, it is fully realized that this is a rather arbi- 
‘trary criterion, but one which is accompanied by such phenomena 
as spore ejection which probably never takes place before maturity. 
On the other hand, the spores become dark and opaque in many 
species some time before they are ejected, while in others (P. 
longicaudata) it is very difficult to find dark brown spores in an 
unruptured ascus. Regarding inaccuracy of observation it may be 
stated that the error here is but slight. Inasmuch as the cultures 
were examined at most every second day and usually every day, 
the error arising from infrequent observations would be under forty- 
eight hours in one case and under twenty-four in the other. In 
many instances, whatever error might occur has been corrected by 
repeated observations on material from various localities 
The periods of development for all the species upon which 
data have been collected are shown on opposite page. 
In all instances where more than one observation was made, the 
shortest period found is quoted. Sometimes this was found to be the 
same for several cultures, but in others a difference of two or three 
days occurred, owing to differences in temperature at the different 
seasons of the year and also to imperfection of observation. The 
shorter periods given in the table represent the most accurate re- 
sults, and it is my opinion that we should look with great suspi- 
cion on any period which extends over twenty days. 
As Sordaria fimicola grows very readily, cultures were grown 
almost continually from July, 1899, to June, 1900, with some 
rather interesting results. The spores of this species as well as 
those of S. humana, Pleurage curvula, P. minuta, and others, grow 
immediately on being removed to favorable conditions, usually 
within twelve hours from planting. Studies made in Van Tieghem 
cells show that all the above species germinate by the protrusion of a 
small globular mass of the content of the spore through the germ 
pore as described and figured by Brefeld,* Miss Nichols* and 
others. From this globular mass the strands of the mycelium 
proper arise. Regarding growth of young immature spores see 
subsequent pages. 
* See Bibliography at close of paper. 
