Lutman—Life History and Cytology of the Smuts. 1193 
stage of development in nearly all the forms. Brefeld (4 & 6) 
in particular has paid attention to spore-germination and the 
saprophytic growth of these forms in various media and has des¬ 
cribed and figured the germination of 56 Ustilagos, 4 Tilletias, 
4 ITroeystis, 4 Doassansias, and 4 Tolyposporiums in 20 plates 
containing over 50 figures. This work stands as a monument 
of industry and thoroughness. He has also described (5) the 
methods of infection and figured the beginnings of the parasitic 
mycelium of the oat, corn and sorghum smut. 
Apparently the first cytological work that was done on the 
group was that of Fiscli (16) and Schniitz (37). Schmitz 
described the mycelial cells of U. longissima as multinucleated 
and stated that when spore formation takes place the hyphae 
break up into segments each containing a single nucleus. The 
spores are formed from these segments and are uninucleated. 
Fisch investigated species of Tilletia, ITroeystis, and IJstilago. 
He found a single nucleus in the spore but multinucleated cells 
in the mycelium. He states that the conidia become multi¬ 
nucleated before they cause infection. 
Hangeard (12) was the next to study the group in its cytologi¬ 
cal phases and it is to him that we owe practically all that we 
know concerning nuclear behavior in the formation and germi¬ 
nation of the spores. 
Dangeard’s (12) first work was a description of spore-forma¬ 
tion or germination in the following species: Ustilago Trago- 
pogi, H. Carbo, IT. violacea, Hoassansia Alismatis, Entyloma 
Glaucii, ITrocystis Violae, and Tilletia Caries. 
He finds that the spores of, IT. Tragopogi arise as short ter¬ 
minal branches of the mycelium, which, by rounding off, form 
the spores. The young spore contains two nuclei. These fuse 
in turn and the mature spore is uninucleated. The germination 
of this spore and that of IT. Carbo are practically the same. 
The nucleus of the spore passes into the promycelium and there 
divides into two and then into four. The promycelium cuts up 
into four cells each of which produced a conidium containing a 
single nucleus. The formation of the spores was not worked 
out in IT. Carbo but was in IT. violacea. The mycelial walls of 
this species at the stage of spore-formation become thick and 
