28 NORTH AMERICAN SORDARIACEAE 
three asci after being mounted before any records were made. 
Continuous observations were then made with the same perithe- 
cium for three hours and twenty minutes. The following fig- 
ures indicate the tinıe at which successive asci were ruptured: 
10:25, 10:46, 11:35, 12:09, 12:53, 1:45, giving periods between 
eruptions as follows: 21, 49, 34, 42 and 52 minutes, respectively. 
The plants had been growing in laboratory temperatures and 
the perithecia were mounted in water of the same temperature. 
These observations were evidently not normal, so other obser- 
vations were made later with the same material which showed 
an eruption in from 15 to 25 minutes at first and gradually in- 
creased as the time of the experiment was protracted. An at- 
tempt was then made to observe the phenomenon on the sub- 
stratum under a low power. This could be done except with 
great difficulty only for a short time, owing to the evaporation of 
moisture from the cultures. Sufficient data were obtained, how- 
ever, to corroborate previous observations. In one case three suc- 
cessive asci erupted in 22, 18 and 28 minutes, respectively. A 
series of three observations on Colorado specimens of the same 
species gave an average of 16 minutes for the first three asci 
erupted after being mounted in water. In one case three asci 
erupted in 20 minutes. The best that can be said then regarding 
the time is that it varies usually from 15 to 25 minutes; and that 
it is probably very materially influenced by temperature and mois- 
ture as well as by the age and general vigor of the plants. 
The distance to which the spores are ejected is now to be con- 
sidered, for the determination of which two methods have been 
employed. The perithecia may be mounted in water as described 
above and the distance measured directly with the micrometer 
scale. The distance in air may then be computed. This method 
has not proven satisfactory in my work, probably owing to the 
interference of the water with the physiological action of the plant. 
The other method consists in placing portions of the substratum in 
a tall moist chamber and catching the spores on the cover of the 
vessel. Adhesive paper was at first used, but this is entirely un- 
necessary because the spores are moist and have more or less 
gelatinous substance clinging to them in the way of appendages 
that they adhere readily to glass. The distance of the cover, on 
