318 Wisconsin Academy of Sciences, Arts, and Letters. 
any reproductive function has never been definitely determined. 
In nearly every case examined the cell contents were vacuolate and 
had apparently degenerated. When the cultures were dried no 
spores appeared and there was no indication of budding from the 
dumb-bell forms when nutrient solutions were added. 
Investigations of the Basidiomycetes have brought forth some 
very interesting results, those of Christman (1905) having been 
considered, especially in relation to the ideas of Clausen on Ascomy- 
cetes. Blackman (1904) finds that in Pragmidium violaceum 
binucleate cells are formed in the aecidium. The spermatia are 
considered functionless. In the aecidium a group of special cells 
form the fertile cells; the fertile cells divide, each one cutting off 
a sterile cell above. The nuclei that' enter the fertile cells migrate 
from undifferentiated mycelial cells and the binucleate fertile cell 
then produces aecidiospores which are binucleate. Nuclear fusion 
does not occur until the teleutospore is formed. Fusion is followed 
immediately by reduction and the formation of sporidia. Similar 
processes were observed in Gymnosporangium clavariaeformae. 
Blackman and Fraser (1906) state that the fertile cells of 
Phragmidium violaceum are female gametes which are fertilized 
by vegetative cell nuclei instead of spermatia. In Puccinia poarum 
nuclear migration begins before the fertile cells are formed. The 
nuclei migrate from one vegetative cell to another and later 
to the fertile cells. Two vegetative cells may form a fertile cell by 
fusion. In Melampsora rostrupi basal cells in the aecidium pair 
and form aecidiospores which are binucleate. Puccinia mal- 
vacearum is apogamous. From all the forms studied they conclude 
that nuclear fusion does not occur in the aecidiospore. The con¬ 
jugate nuclei fuse in the teleutospore and reduction occurs 
during the formation of sporidia, a process which may be consid¬ 
ered a true alternation of generations. In Humaria rutilans no 
male cells function, but the female nuclei of the multinucleate 
aseogonium fuse in pairs. Whether this process can be considered 
analogous to that of Phragmidium violaceum is questionable. 
Bensaude (1918) investigated the nuclear behavior in certain 
Basidiomycetes. She finds that the mycelium is heterothallic, a 
-f- spore and a — spore must develop in sufficient proximity in 
order that fusion of the cells of the hyphae can be accomplished. 
Binucleate cells are formed but' fusion of nuclei does not take place 
until the basidium stage is reached. Fitzpatrick (1918) and Gil¬ 
bert (1910-11) (1921) have found that the hyphal cells of the 
