1218 Wisconsin Academy of Sciences, Arts, and Letters. 
cells may vary in the smuts or there may he a non-septate 
promycelium as in the Tilletias, still as Brefeld (6) has shown, 
there are variations in the basidia, especially those of, the Tre- 
mellineae, which are perhaps parallel in some degree to those in 
the rusts and smuts. An exhaustive study of the basidium in all 
its forms has been made by Brefeld and the system of classifica¬ 
tion which he worked out is the quite commonly accepted one 
today for the groups of the Ustilagineae, TTredineae, and Basid- 
iomycetes. 
Our belief in the relationship of these three groups was still, 
further strengthened by the discovery by Dangeard (12) and 
Sappin-Trouffy (36) that the formation of both teleutospore 
and chlamydospore was preceded by the fusion of two nuclei in 
the young spore which made a striking parallel to the fusion of 
the two nuclei in the young basidium. 
It has now been well established that this fusion of two nu¬ 
clei in the teleutospore of the rust and a similar fusion in the 
young basidium is universal for the two groups having these or¬ 
gans. And my results on the smuts above described confirm the 
views of Dangeard, Maire, and Raciborski that a similar fusion 
occurs regularly in the chlamydospore of the smuts. Microtome 
sections bring out very clearly as described, the great difference 
in the spore formation of the two divisions of the smuts: the 
Tilletiaceae and the ITstilaginaceae. In the latter group an en¬ 
tire group of hyphae break up into spores, while in the first the 
spores are borne as side branches or at the tip of the main 
hyphal branches. 
The question whether the nuclear phenomena are the same in 
the two cases is a difficult one. Dangeard (12 & 13) has found 
a nuclear fusion in the formation @f the spores of Doassansia 
Alismatis, Entyloma Glaucii, and Urocystis Violae of the Til¬ 
letiaceae; Maire (30) has found it in Tilletia Tritici, and 
Raciborski (34) in Entyloma Eymphaeae. In my own work I 
have been able to confirm the existence of the fusion in Doas- 
sausia Alismatis and Entyloma ETymphaeae and to show that it 
also occurs in Urocystis Anemones and Doassansia deformans. 
Practically all of the most decisive work has been done on this 
division of the smuts,, while little has been done on the other. 
