Lutman—Life History and Cytology of the Smuts. 1219 
Dangeard definitely asserts that a fusion occurs in TIstilago 
Tragopogi; in IT. Violaeea there are two nuclei present and 
sometimes only one hut it is impossible to see the fusion. The 
reason for this uncertainty is, of course, the small size of the 
cells and nuclei. My own observations indicate that a fusion 
occurs in the young spores of TIstilago levis and U. Zeae. But 
further evidence is needed to make it perfectly clear that the 
same nuclear conditions are present in both groups. It may be 
that there are species with larger cell and nuclei that are more 
favorable for study than those of the species studied so far. 
Soon after the discovery that the two nuclei fuse in the basid- 
ium and teleutospore, appeared the additional fact from the 
work of Sappin-Trouffy, Ruhland, Maire, and Harper that the 
mycelium from which the teleutospores and basidium arise is 
binucleated and especially that the sub-hymenial cells are bi- 
nucleated. It is fairly well established that the two-nucleated 
stage in these fungi represents the sporophyte generation in 
their life history and hence it is of the first importance to dis¬ 
cover whether in the smuts this condition of the cells is limited 
to the spore alone or whether it extends throughout a large part 
of the mycelium. Previous authors have done little on the 
nuclear conditions in the mycelium. All that we have are the 
statements of Dangeard (12), Fisch ( ; T6), and Schmitz (37) 
that the mycelium is composed of multinucle&ted cells. 
My observations show, however, that while this statement that 
the mycelium is made up of multinucleated cells is probably 
true of the genus TIstilago it is probably not true of the Tilletia- 
ceae. Entyloma Hymphaeae has binucleated cells. The same 
is probably true of Urocystis Anemones, Doassansia Alismatis, 
and Doassansia deformans; at least many binucleated cells are 
present in the later stages. Maire (30) also has made the 
statement that the spores of Tilletia Tritici arise from binucl^ 
ated cells in the mycelium. Dangeard’s figures of spore forma¬ 
tion in Urocystis Yiolae, Entyloma Glaucii, and Doassansia 
Alismatis (12) show a mycelium in which the cells nearly all 
have two nuclei associated together. 
It is true that all these observations relate for the most part to 
the time of spore formation and that this binucleated condition 
