6 
Journal of Mycology 
[Vol. 9 
UREDINEOUS INFECTION EXPERIMENTS IN 1902.P) 
W. A. KELLERMAN. 
( 2 ) A series of sixty-seven experiments were carried on in 
1902, beginning April 7 and ending June 24. All were performed 
with host-plants previously transferred to the greenhouse, and 
were at the time of attempted inoculation, with few exceptions, 
in a satisfactory growing condition. Plants not removed from 
their natural habitat were used later in the season in a very 
few cases, but the method of procedure in the experiments was 
the same as that followed in the greenhouse. 
Seventeen forms of Uredines were used in the inoculations. 
Of these seven yielded satisfactory results. In a case of two so 
meagre evidence was obtained that it is best to regard them, if 
artificial inoculations at all, at least as undecisive. 
Infections were made in the usual way, namely by moisten¬ 
ing the supposed host-plant by means of an atomizer; then de¬ 
positing on the tender growing portions a quantity of the spores 
supposed to be viable. The plants were immediately covered 
with a bell-jar or suitable substitute therefor — this removed 
daily or oftener, but only long enough to repeat the use of the 
atomizer. After ample time for germination of the spores the 
covers were discarded. 
Precautions were taken to guard against possible accidental 
infection. Spores of only one Rust species were used on any 
one day, and so far as practicable scalpels, forceps, camel’s-hair 
brushes, and watch crystals were used but once; or if again 
needed were called into requisition only after thorough cleansing 
and disinfection. 
At any one part of the work table or bench in the green¬ 
house, inoculations were never made with more than one species 
of Rust. It was feasible to carry on the work in different places, 
as in different sections of the greenhouse, different laboratory 
rooms, etc. This was believed to be a safeguard — possibly 
over cautious — against accidental infection. 
In the earlier experiments a cover for the host-plant, a cyl¬ 
inder 18 to 20 inches high made of coarse wire netting and sur¬ 
rounded with muslin, was very satisfactory. Later, when the 
greenhouse was more freely ventilated, the evaporation was too 
rapid, and bell-jars or suitable frames made of narrow strips of 
galvanized iron with glass sides and tops were substituted. The 
plants were usually kept covered 3 or 4 days — or even 5 or 6 
P) Contributions from the Botanical Laboratory of the Ohio State 
University. XI. 
( 2 ) The substance of this paper was presented before the Botanical 
Society of America, Jan. 1, 1903, under the title Uredinous Infection: 
Suggestions and Experiments. 
