Germination of Teleutospores of Ustilaginee. 77 
part of their length ; or the end of one may become united 
with the central segment of another, and so forth (Fig. 5). 
These various fusions take place only in spores grown in 
water. Brefeld has shown, however, that when cultivated 
in a medium which is capable of supplying suitable nutri- 
ment to the spores, these various fusions do not take place. 
He discovered that an aqueous extract of the excreta of 
herbivorous animals, sterilized by discontinuous boiling, 
afforded such a medium (ndhrlisung). Spores of U. sege- 
tum placed in Brefeld’s nutrient fluid germinate sooner 
than in water. Not only so, but the promycelia and the 
promycelial spores are larger than those produced in water. 
No fusion of spores or buckling of promycelia occur. The 
most remarkable fact is that the promycelial spores mul- 
tiply themselves by budding, very much after the manner 
in which yeast-cells multiply themselves in saccharine fluids 
(Plate VII. Figs. 8-10). Brefeld has kept them thus repro- 
ducing themselves for more than a year, by replacing the 
nutrient fluid as it became exhausted. The promycelial 
spores continue to reproduce themselves by budding, as 
long as the nutrient fluid remains unexhausted ; when this 
occurs they cease to bud, and fuse in various ways, as is 
seen when germination takes place in water. The yeast- 
spores of this species produced in his nutrient fluid are 
rather larger than the primary spores produced from the 
promycelium in water; they are, however, of the same 
shape, and measure from 9 to 30m in length, and from 
3 to 5in breadth.* Kept moist, they retain their vitality 
for about two months, but if allowed to dry, none germi- 
nated after the sixth week. The teleutospores, on the 
contrary, if kept dry, retain their germinative faculties for 
a very long period. Brefeld found that at the end of two 
years they germinated as freely as when fresh; other 
* Brefeld, loc. cz#., p. 13. 
