Jan. 1, 1925 
Composite Life History of Puccinia podophylli Schw. 71 
the late crop of teliospores, four plants 
showed pycnia and aecia on the leaves 
in numerous spots, some of which on 
all four plants in later stages of develop¬ 
ment showed accompanying telia. In 
the pots mulched with soil from the 
infected patch one plant showed a few 
pycnia and abundant telia on sheath 
and stem, together with pycnia and 
aecia on the leaves in numerous spots 
in association with which telia were not 
uncommon, and the other plant showed 
numerous spots with pycnia and aecia, 
with some of which were associated 
telia. In all cases where telia accom¬ 
panied the aecia on the leaves they were 
most commonly found on the veins 
which were involved in the areas of 
aecial infection. A control series of 
pots in which the rhizomes were 
mulched with ordinary potting soil 
showed no infection of any sort. 
Experiment 4.—In this experiment 
overwintered teliospores from the late 
crop on the leaves, which by previous 
test were known to be germinating, 
were sown at three different dates on 
Podophyllum plants taken from an 
uninfected patch. This work was all 
done in the greenhouse. The first 
sowing was made on April 27, 1918, on 
leaves and stems of four plants, three 
of which had the folded leaves well out 
of the sheaths and the fourth just 
emerging. The result showed devel¬ 
opment of pycnia and aecia on leaves 
of all plants and telia on the stem of one. 
Epiphyllous telia developed in a num¬ 
ber of the aecial areas, mostly on the 
veins. The second sowing was made 
on May 6, 1918, on six plants of 
Podophyllum all of which were well 
out of the sheath, with the leaves 
partly expanded. Pycnia and aecia 
were developed on the leaves of all 
plants. Some of the aecial lesions on 
each plant showed telia in immediate 
association. In one case telia were 
developed in association with pycnia 
without aecia being present. In the 
third sowing on May 11, made on the 
leaves of more mature plants, numerous 
lesions bearing pycnia and aecia devel¬ 
oped on two of the plants. Telia 
were also developed later in association 
with the aecia on a majority of the 
spots. On both plants a few spots 
containing aecia developed in associa¬ 
tion with which no pycnia were 
observed. 
Experiment 5. —This experiment 
dealt with the infection from aecio- 
spores. Three sowings were made 
under control conditions in the green¬ 
house. The first sowing was made on 
May 28, 1917, using aeciospores col¬ 
lected in the field from plants which 
showed only aecia and with which no 
pycnia were observed. The inoculation 
was made on the expanded leaves, and 
fully mature telia developed on June 9. 
The second sowing was made on May 
3, 1918, using aeciospores from plants 
collected in the field on which the 
aecia were accompanied by pycnia. 
Sowings were made on one mature 
plant and three younger plants. An 
attempt was made to inoculate the 
sheaths and stems as well as the 
leaves. Telia appeared, however, only 
on the leaf blades of the three younger 
plants, being fully mature on May 20. 
A third sowing was made on May 10, 
1918, using aecia obtained from the 
inoculations described in Experiment 
3. The inoculation was made on 
several plants in various stages of 
maturity. Telia developed only on 
the leaves of the younger plants. 
In all of these sowings the telia ob¬ 
tained were of the type occurring gre¬ 
gariously in spots on the under side of 
the leaves, commonly found in the 
field in midsummer, and referred to in 
this paper as the late crop of telia. 
These experiments confirm those of 
Arthur (1) and effectively dispose of the 
idea that repeating aecia might be pres¬ 
ent in the life history of the Podophyl¬ 
lum rust. 
Later Experiments. —During 1919, 
1920, and 1921, other experiments were 
conducted, which confirmed the results 
of those outlined above in all details. 
In a few cases telial material which was 
observed to be germinating in hanging- 
drop tests was transferred to the plant. 
The results were the same as where less 
refined methods were used. 
It may be noted that only a few 
records of infection on the sheath 
leaves are made in these experiments. 
This, it should be explained, is due to 
the fact that some difficulty was en¬ 
countered, under rather dry greenhouse 
conditions, in preventing the sheaths 
from drying up before the telia devel¬ 
oped. In many such cases, however, 
evidence of infection was observed, and 
in the later experiments of 1919 to 1921, 
this phase of the problem was given 
special attention. 
SUMMARY OF RESULTS OF 
EXPERIMENTS 
A careful analysis of the results of 
these experiments shows that the writers 
have obtained the development of telia 
on sheaths and stems, and pycnia and 
aecia with associated telia on the leaves, 
by inoculating with germinating telio¬ 
spores of both the early and the late 
crops. 
