Basidiospores of Polyporus pargamenus in different positions, X 3,000. 
ew, the apiculus lying to the right side; r, right lateral view, the apiculus lying to the 
ft side; v, ventral view, the apiculus lying in the symmetry plane; d, dorsal view, the 
piculus not being visible in this view; g, transverse section at the central elevation. 
The Biology of Polyporus Pargamenus Fries 65 
or ventral side to the lateral position, just so much the more 
does it approach the exact symmetry of the allantoid form, 
while the apiculus changes again to the lateral position. 
The transverse diameter of the spore remains approxi- 
mately the same in the different changes of the indicated 
positions; at least no noticeable differences could be detected 
with the measuring devices at my disposal. Therefore it 
may be inferred that the cross-section (basipetal view) must 
exhibit an approximately circular contour, which can be 
corroborated by direct microscopic examination from above 
or below (Fig. 5, q). 
The spores consequently are basipetally bilateral in trans- 
verse section; in longitudinal section they are bilaterally 
symmetrical dorsiventrally and strongly unequally halved 
laterally. They appear colorless by transmitted hght and 
white by reflected hght. 
Era.. 3. 
9 
v 
1, left lateral 
