20 
characteristics, particularly in separating otnerwise somewhat 
similar species. 
On germinating these chlamydospores the large, penultimate 
cell, and that one only, put out a mycelium. From its thick 
walls one might have concluded that it was a resting spore, like 
so many other chlamydospores, but it appears to be the spore 
form which serves for the rapid reproduction of the fungus, for 
it germinated in every case within forty-eight hours, usually in 
much less. The further development of the mycelium it 
formed was determined chiefly by the food supply available. 
Thus, if the spores were sown on an extract of peas, made up 
with ten per cent. of gelatine, the mycelium grew slowly and 
remained altogether sterile, though transferred repeatedly to 
fresh supplies of pea extract. The sterile mycelium could, how- 
ever, be induced to form a fresh crop of the chlamydospores if 
placed on pieces of sterilized chestnuts. 
When germinated in beer-wort gelatine the mycelium pro- 
duced the characteristic chlamydospores once more, but the 
submerged hyphz, instead of remaining thread-like, became 
shortly septate, and some of the barrel-shaped cells so produced 
grew up into balloon-like structures, 100u in diameter, whose 
walls either thickened considerably and became carbonized, or 
broke and set free what appear to be myriads of minute oil 
drops. The general appearance strongly suggested an attack 
by some fungus near the Chytridiacew, but subsequent 
investigation showed that this was not the case. The result 1s 
probably pathological, and determined by the amount of sugar 
present, for cultures of the fungus in 5 per cent. glucose, or 
cane sugar, give pure cultures of this form only. 
When the chlamydospores were sown on a watery extract of 
chestnuts, made up with agar-agar, a further crop of chlamy- 
dospores were produced, and at the same time the submerged 
hyphe gave rise to small bunches of flask-shaped swellings, in 
the tips of which small conidia were formed, and shot out every 
three or four hours. By keeping down the available food 
supply, by using very dilute watery extracts, the formation of 
the chlamydospores could be checked, and_ practically pure 
cultures of this peculiar conidial stage produced. Later on, 
particularly when the extract was not too dilute, these cultures 
gave rise to spore-balls so similar to those of Urocystis violae, 
that I could not find a single characteristic to separate them by. 
They contained a variable number of thick, brown-walled 
chlamydospores (1-6 as a rule), invested by a single layer, of 
thin, almost colourless, envelope cells. | A somewhat similar 
spore form was also found on examining the cultures on pieces 
of chestnuts. In these spore-balls the chlamydospores were far 
