LEVINE: CyTOLOGY OF HYMENOMYCETES 139 
R. Hartig (1885) however believed that such cell unions resemble 
a sexual act and he compared these phenomena with the fusions 
in the Conjugatae. He traced the development of Merulius 
lacrymans from spore to spore and describes hyphal anastomoses 
and clamp connections as common in its mycelium and crustlike 
carpophore. Meyer (1896-1902) describes the formation of 
hyphal anastomoses in Hypomyces rosellus. He states that 
when one hyphal cell comes in contact with another a fusion may 
take place. The walls at the point of contact disappear and the 
protoplasm of the two. unite. Soon afterward a new wall is 
formed which only incompletely separates the two cells. Meyer 
believes that the fusions of hyphae by anastomoses, involving the 
fusion of plasms not closely related, may have the same effect 
as cytoplasmic fusion in a normal fertilization. In view of the 
well established fusions found in the rusts, Voss’ claim (1903) that 
clamp connections and hyphal anastomoses are also present in 
this group has considerable interest. His observations, so far 
however, have not been confirmed. 
Ordinary pit connections for the transfer of food materials are 
undoubtedly present in the cross walls of the hyphae of all the 
higher fungi. Strasburger, 1884, maintains for Agaricus campes- | 
tris, that the cells in the stipe show so-called protoplasmic con- 
tinuity. 
Miss Wakefield’s (1909) observations on the conditions: 
governing the production of the carpophore in Schizophyllum 
commune and Stereum purpureum are quite in harmony with the 
view that the origin of the carpophore in the Hymenomycetes 
is in no way associated with a sexual act. She finds that the 
production of carpophores depends upon the rate of transpiration. ° 
Thus carpophores are produced when transpiration is slow while 
none are formed when evaporation is too rapid. 
The determination of the number of nuclei in the hyphal 
cells and the more exact study of their behavior has led to quite 
new conceptions as to the presence of sex in the Basidiomycetes. 
De Bary (1866) first observed the nucleus of the basidium in 
Corticium amorphum. Strasburger (1884) using alcohol and alum 
haematoxylin was able to demonstrate, beyond a doubt, that 
there are nuclei in the hyphal cells of Psalliota campestris and in 
