82 British Uredinea and Ustilaginea. 
According to Brefeld,* it is seldom that more than three 
promycelial spores are produced from one teleutospore 
before it becomes emptied of protoplasm and exhausted. 
Be this as it may, if a few teleutospores be placed in a 
drop of water on a glass slide, and examined at intervals 
for two or three days, one can see with the naked eye that 
there has fallen to the bottom of the drop a whitish cloud. 
Upon microscopic observation, this cloud is found to con- 
sist of an immense assemblage of promycelial spores. 
They are cylindrical bodies, with somewhat attenuated’ 
extremities, and often measure from 8 to 10m in length, 
and from 1°§ to 2u in breadth. Hence it appears that 
they have increased in size since they fell off the pro- 
mycelium. After a time this increase in size ceases, but 
not before some few odd ones here and there have attained 
a length of from 20 to 30pm. 
Brefeld found, by the culture of isolated promycelial 
spores in nahrldsung, that after these bodies had fallen away 
from the teleutospore which produced them they not only 
multiplied themselves, but increased enormously in length 
and thickness. This they did with great rapidity. They 
more resembled hyphe than promycelial spores, and each 
soon became more or less septate. They multiplied by 
giving off a small bud-like projection laterally, and at a 
short distance from one or other of their extremities. This 
bud rapidly grew into a second spore, but before it attained 
the dimensions of its parent the latter had given off a 
similar bud towards its opposite extremity; and so the 
process of multiplication goes on until the nahrlésung is 
exhausted. When this takes place, instead of multiplying 
in the manner above described, the promycelial spores give 
off hyphz of considerable length, which become septate at 
intervals from below upwards, and the protoplasm is passed 
* Brefeld, /oc. cé¢., pp. 104-116, t. viii., ix., figs. 1-16. 
