324 DorAN: ON THE GERMINATION OF FUNGOUS SPORES 
For these several groups of fungi the minimum temperatures 
for spore germination occur between 1° and 7.4° C. The opti- 
mum temperatures are all between 13° and 23.1° C. The maxi- 
mum temperatures for the germination of the spores occur 
between 22° and 39.6° C. The Phycomycetes have the lowest 
minimum temperatures, followed in order by the urediniospores, 
the aeciospores and the teliospores of the Uredinales. Teliospores 
and the sporesof the Fungi Imperfecti have the highest, and about 
the same minimum temperature for germination. 
Of these five groups of fungous spores, aeciospores have the 
lowest optimum temperature for germination followed in tura 
13 616.2 18 a i 23.1 
100 x 
/\, 7 \ s aN 
99) PER CENT Bat Aes PHYCOMYCETES 
st : : AECIOSPORES —---——-— 
oy RRR UREDINIOSPORES +++ 
70 ELIOSPORES —*—x—*— 
FUNGI IMPERFECTI-~~~-~ 
60 
50 . 
40 
™ ae 
20 ~ 
* \ x 
; fs ‘ < 
e / f oa tet tae \. 
© A23Z45 6574 is 162 18 20-22-24 26 wiss 396 
Fic. 1. Curves showing the rin temperatures for the germination 
of the spores of representative fung 
by urediniospores, conidia of Phycomycetes, teliospores, and 
then by the spores of the Fungi Imperfecti, which seem to have 
the highest optimum temperature for germination. 
Aeciospores have the lowest maximum temperature for 
germination, and the spores of the imperfect fungi have the 
highest. About midway between these two come urediniospores. 
Their maximum temperature for germination is higher than that 
of the conidia of the Phycomycetes. 
The spores of the Fungi Imperfecti can, it would appear, 
germinate through the greatest range of temperature. As com- 
pared with this, the range of the Phycomycetes is 77 per cent 
