SPORE DISCHARGE OF PLEURAGE CURVICOLLA 
77 
In another experiment the opening in the paper was cm. in diameter 
and about 5 cm. from the bottom of the flask. The spore masses were 
found mostly within this circle, but a few were scattered in all directions 
about the opening; however, they were all included within a circle cm. 
in diameter concentric with the opening in the paper. The flask was then 
turned about so that the opposite side was exposed to the light through the 
opening in the paper. After 45 hours the paper was removed, and the same 
conditions as described above with regard to the arrangement of the spores 
about the opening were found to have been duplicated. In one experiment 
a grayish-black, instead of a jet-black, paper was used to exclude the light. 
In this case the spores, instead of being discharged towards the opening in 
the paper, were discharged against the side of the flask almost opposite 
the opening. This paper behind the glass acted as a mirror and it would 
seem that the reflected light exerted a stronger heliotropic influence than 
did the direct light. In this case the spore print covered an area on the side 
of the flask opposite and slightly below the source of light about six times 
larger than the area of the opening in the paper. The flask was then turned 
about, exposing the opposite side to the light, and the spores were again 
shot away from the direct light. However, when the paper was removed 
entirely the spores were discharged towards the window. 
Duller shows that the great distance to which Ascoholus immersus spores 
are projected in comparison with that traveled by the spores of the Hymeno- 
mycetes is due to the large size of the spore mass. The size of this spore 
mass, he states, is due (i) to the unusually large size of the spores; (2) to 
the thick gelatinous envelope round each spore ; (3) to the clinging together 
of the spores; and (4) to the large mass of the discharged ascus sap. In 
the case of Pleurage curvicolla there are approximately 500 spores all clinging 
together and discharged as one body together with a quantity of ascus sap 
or other gelatinous substance, making a large projectile. A number of 
spore prints made upon a microscopic slide placed over the mouth of the 
two-Hter culture flask 26 cm. above the fruiting surface were measured. 
These were circular in outline and ranged from 168 to 266 ^ in diameter. 
Surrounding each spore mass was a sort of halo about 25 to 30 wide due 
to the gelatinous substance in which the spores were imbedded and which 
was discharged along with them. No doubt the comparatively great mass 
of material discharged in this instance, as in the case of Ascoholus immersus, 
is a big factor in determining the distance to which the spore masses are 
shot. 
Pleurage curvicolla probably can project its spores to a greater height 
than any other Ascomycete yet studied. Its spores are usually discharged 
in masses towards the source of light, but reflected light seems to exert a 
stronger heliotropic stimulus than does direct light. 
