Harper—Species of Lentinus in Great Lakes Region. 377 
shown in Plate XXI, C has the gills partially parasitized and the 
one in figure B wholly so. They grew on stumps of bass wood at 
Geneseo, Illinois. 
The plants of this group, like those of the Lentinus lepideus 
group, show many monstrosities (see Nuov. Giorn. Bot. Ital. 1895, 
p. 56). Lyman also in the cultures referred to below produced 
many monstrous forms. 
The nature of the form with abnormal gills has been much dis¬ 
cussed since Morgan claimed that it was autonomous and named it 
Lent odium squamulosum. The most critical work on the subject 
has been done by George R. Lyman in his Studies on Polymorphism 
of Hymenomycetes (Proc. Boston Soc. Nat. Hist. 33: 181-193). 
Lyman succeeded in growing Lentodium squamulosum from the 
spores and produced carpophores with abnormal gills like those 
from which the spores were taken. He agreed with Morgan as to 
the autonomy of the form for two reasons: first, because it had 
never been found growing with Lentinus tigrinu$, nor had inter¬ 
mediate forms been reported. Second, because of the permanence 
of its essential peculiarities in cultures. The first reason does not 
hold, for Dr. Moffatt and I have found abundance of normal forms 
of several varieties and also forms with the gills partially covered 
and partially free. As to the second reason, Lyman does not dis¬ 
cuss the possibility of the ‘ ‘ veil, ’ ’ as he calls the mass of mycelium 
covering the gills, being the hyphae of a parasite. The conidial 
spores which he finds on this veil may have been present in the 
sowings. To make the evidence complete, cultures should have 
been made from normal forms and then from mixtures of the 
spores from both forms. 
The connection of the normal and the abnormal forms as they 
are found about Chicago and Geneseo strongly suggests a para¬ 
site, especially as several different forms of the fungus have their 
gills affected in the same way. 
The resemblance of the affected carpophores to species of Agarics 
and of Boleti parasitized by Hypomyces is very striking. The 
gills or pores are deformed and covered with a very similar cot¬ 
tony veil. The parasite appears to be a Hyphomycete of a genus 
like Verticillium or Spicaria, constituting the conidial stage of a 
Hypomyces the ascigerous stage of which does not develop or has 
not been discovered. The spores of the plants with normal gills 
are more even in size and as large as the larger spores in the 
forms with abnormal gills, 3 x 7-9//,. Very many of the much more 
