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150 LEVINE: CYTOLOGY OF HYMENOMYCETES 
species were Polyporus adustus, P. betulinus, P. destructor, and 
P. versicolor. The first two and the last were also studied by 
Miss Cool (1912). The material was propagated by transferring 
small pieces (2-5 mm. sq.) of the mycelia from each culture to a 
variety of agar media. Soft malt-beef and cherry agars proved 
the most favorable. Parts of such mycelia were fixed in Flem- 
ming’s, Juel’s, Bouin’s, and Hermann’s solutions but the most 
favorable results were obtained with Flemming’s weaker solutions. 
Clamp connections are of course abundantly present in the cells 
of these mycelia. I did not specially study the development of the 
clamps, but it is plain that the mature clamp is not cut off from the 
two cells which it joins, as Brefeld (1877) held for Coprinus ster- 
corarius. Only one cross wall is formed separating the clamp 
from the cell from which it arose. In well stained preparations 
hemispherical pads similar to those described above are visible 
on both sides of this cross wall in the clamp. This perhaps indi- 
cates only a partial closing up of the opening originally present. 
Similar pads may be seen also on the septa between many of the 
hyphal cells (pL. 4, FIG. 8). Hyphal anastomoses in these my- 
celia are also common. The hyphae of these Polypores (PL. 5; 
FIG. 5, 6) are made up of a series of regularly binucleated cells. 
In the mycelium of Polyporus versicolor (pL. 4, FIG. 8) un- 
doubted uninucleated cells are also present but they are not com- 
mon; the mycelia in cultures of P. destructor and P. betulinus (PL. 
4, FIG. 7) may show non-nucleated cells which are joined to adja- 
cent binucleated cells by hyphal anastomoses and clamps. 
I have also studied the cells of Coniophora cerebella, also ob- 
tained from the Association Internationale des Botanistes. They 
are regularly binucleated; clamps and hyphal anastomoses are 
also present. 
It is plain that the binucleated condition is fixed in all these 
forms long before they proceed to the formation of a carpophore. 
My mycelial cultures all showed on their surfaces the familiar 
appearance of droplets of water, varying in size from small glob- __ 
ules 0.5 mm. in diameter, to large ones 10 mm. in diameter. The 
small drops are countless while the large ones are relatively few- 
Regarding Knoll’s (1912) contention that many of the Basidio- 
mycetes are provided with sp cial hair-like organs, trichome-hyda- 
