Lutman—Life History and Cytology of the Smuts. 1211 
a considerable distance and in this position can be studied to ad¬ 
vantage. They seem to have two nuclei which lie rather close 
together, and while the ends of the cells cannot in the majority 
of cases be made out; in some cases (Fig. 46) they can, and in 
these cells the binucleated condition can be determined with cer¬ 
tainty. Further, the young hyphal branches from which the 
spores seem to arise seem to be binucleated in some of the few 
cases that I was able to trace. If the fungus does not have bi¬ 
nucleated cells universally, at this stage of development, there is 
at least a strong tendency toward the binucleated condition. 
An interesting fact with regard to the germination of the 
spore-balls was brought out in examination of sections of rather 
old infected spots of the leaf. Brefeld (6) has described and 
figured the germination of the spores in water after the spore- 
balls have been teased out or after the ball has been broken up 
but does not describe the germination in situ in the leaf. When 
the free spore-ball germinates after being freed from the leaf it 
pushes out its promycelia in a radial manner all over the surface 
of the ball between the sterile cells. In germination in the leaf 
(Fig. 48), however, and this may apparently occur as soon as 
the ball is mature, a break occurs at one point on the surface of 
the ball, usually on the side nearest the leaf epidermis, and is 
due to the first promycelia wedging the sterile layer apart at that 
point; the figure that is formed being almost an exact reproduc¬ 
tion of the one given by Magnus (27) for Setchellia puncti- 
forinis (ISTiessl) Magn. The promycelia are always long enough 
to reach the exterior and protrude from this opening so that they 
may bear their tufts of conidia at the apex, exteriorly to the sur¬ 
face of the leaf. This confirms Setchelhs (38) statement that 
the balls germinate immediately after formation. 
Doassania defornums (Setch). 
The material for this work was fixed and sent to me by Dr. J. 
J. Davis of Racine, Wis., where it occurred on Sagittaria varia- 
bilis. It was imbedded, sectioned, and stained in iron-haema- 
toxylin or the triple stain. 
