i 
Biology of tho Uredinee. 453 
1 minis to the action of various solutions in their germination, 
compared with spores of other fungi, with which he also ex- 
perimented: ‘‘The spores of various fungi show unlike powers 
ofresistance against solutions of metal-salts and acids. The 
conidia of Peronospora viticola prove to be the most suscep- 
tile of the forms investigated. Then, following these, in the 
order of decreasing sensibility, are the conidia of Phytophthora 
infestans, eecidiospores of Puccinia graminis, conidia of Cla- 
weeps purpurea, spores of Ustilago Carbo, and uredospores of 
Pucinia graminis.”®> According to this statement, uredo- 
spores have, comparatively, great powers of resistance to varl- 
ous solutions, and there is the further fact that «wcidiospores 
ate much less resistant than uredospores, both of which facts 
are further established by my experiments, So far as I have 
gone, 
They are also similarly resistant to extremes of cold. It 
was already well known that the mycelium of Puccinia Ru- 
in the tissues 
time Bee ination would probably have ee 
tulatury ane, but was not attempted. agyy oe 
Ell. & Kell. is still producing ecidiospo / 
a otal out doors, a M 
os r, & 
“he a oe se has seen in December 
bnpe Pores on specimens of this host gro 
beg Owdrift. kn the spring, zecidiospore 
] ag forming about the first day of April. 
|. ‘See 93. : 
ley, Bieter . Handbuch der Pflanzenkrankheiten, 
. TH - 
um Pentstemonis Schwein., and uredospores of Uromy 
ok 
*C, tra 
8 anslated from Pp. ed, 2. IL 216; and Bol- 
i. 
Mee Ball Wag oa nd, 70, 93a e fall Biscussion OF this matte 
