28 Journal of Mycology [Vol. 11 
May 12th on the plants three or four inches high but the stalks 
fifteen inches high did not exhibit inoculation. 
Uredospores from the Dent Corn were then used on Dent 
Corn both white and yellow, also on Sweet Corn and on Pop 
Corn (Expts. 294, 295, 296, 306, 308, 323, 324, 325, 356, 384). 
In all cases success attended the inoculations. It was evident 
by this time that we had scarcely to think of a probability of 
“biological” forms or varieties seeing that in case of at least 
three of the so-called “agricultural species” of Maize there was 
no invulnerability to one and the same individual Rust-plant, if the 
expression be allowed. 
Effort was then made to secure all of the “agricultural spe¬ 
cies” of maize and attempt inoculations using uredospores of the 
several kinds of host plants now available. Several repetitions 
of previously outlined combinations were successfully made 
(Expts. 292, etc.) 
On May 15th uredospores which had been harvested on 
yellow Dent Corn (these having been obtained by sowing the 
uredospores from Sweet Corn that were the result of inoculation 
with the teleutospores from Sweet Corn plants of the previous 
season, were sown on young Pod Corn plants, (Expt. 355). Sori 
of uredospores followed May 23. This experiment was repeated 
with success May 22-29 (Expt. 383). 
On the same date (May 15) uredospores (of the same pedi¬ 
gree as those mentioned in the preceding paragraph) were sown 
on small plants of Flour Corn and on corresponding date, viz., 
May 23, uredo pustules appeared, (Expt. 357). Repetition of 
such inoculation was successful, date June 4-15. 
For the sake of zeian chronological consistency it may be 
stated here that on date now mentioned, May 15, teleutospores 
from Sweet Corn (same as used in first experiment) were sown 
on Dent Corn and on May 28 uredosori appeared, (Expt. 361). 
This result is a confirmation of the previous conclusion (result 
of Expt. 261), namely, that two spore producing stages only are 
included in the Maize Rust life cycle — based, however, it must 
be remembered, on two tests only! 
Again, using the uredospores obtained by the first inoculation 
experiments of the season, this time the host being Flint Corn, 
abundant success followed. In fact from this time on, many 
plants of Flint Corn, as well as the other kinds used as hosts, 
became inoculated when placed in close proximity to plants well 
infected by previous experiments. 
It may be stated that uredospore-formation continued as 
long as the host-plant grew thriftily. But when the latter de¬ 
clined so that the leaves began to turn yellow, pustules of teleuto¬ 
spores appeared. 
