1192 Wisconsin Academy of Sciences, Arts , and Letters. 
ber of nuclei in the cells of tbe mycelium is scattering and frag¬ 
mentary. 
The earlier papers on the smuts described, of course, only the 
external features of the mycelium and of spore-formation and 
germination. Prevost (33) in 1807 by germinating the spores 
of Tilletia Caries was able for the first time to recognize with¬ 
out a doubt that this disease of wheat was due to a vegetable 
parasite. He was able also to observe the germination of the 
spores of Ustilago Carbo from oats. His work was confirmed 
by Cor da and Tulasne (39-40) who by using his methods were 
able to germinate the spores of additional species. Tulasne 
published his results in quite an extensive monograph of the 
group which covered not only classification but also many points 
in the life history of a number of species. 
Fischer von Waldheim (41) described and figured spore for¬ 
mation and the external appearance of the mycelium in a num¬ 
ber of species of Ustilago, Tilletia, and in one species of So- 
rosporium. Winter (42) figured the mycelium and spore for¬ 
mation in Geminella Delastrina and Urocystis Colchici as well 
as in several species of Ustilago. Cornu (11) in 1883 des¬ 
cribed the structure of the sori and spore formation of Doas- 
sansia Alismatis and D. Farlowii, and in 1892 Setchell (38) 
monographed the genus Doassansia adding many new points as 
to their spore-formation and life-history. 
Some of the more recent work especially that of a semi-popu¬ 
lar nature contains descriptions of the mycelium and spore-for¬ 
mation of some of the species that are destructive to cultivated 
plants. Miss Knowles (26) has shown the mycelium and spore- 
formation of the corn smut in her paper on the abnormal struc¬ 
tures produced by it. Clinton (10) worked out the life-history 
and spore-formation in Cintractia Sorghi-vulgaris of the broom- 
corn. 
On account of the ease with which the spores germinate this 
was one of the earliest facts observed in the life-history of the 
smuts. Prevost (33), Cornu (11), Tulasne (39-40), De Bary 
(14), Fischer von Waldheim (41) and a great number of recent 
investigators have germinated the spores until now we know this 
