Nov. 15, 1925 
Longevity of Teliospores of Oronartium ribicola 
913 
It should be noted in Table IV that the tests of collections 3, 6, 
10, 11, and 13 stopped abruptly before the limit of viability was 
reached. This was due to the lack of material which was scarce at 
the time of collection. 
The germination tests given in Tables IV and V were made at 
7-day intervals. Accordingly a lot of material which is said to have 
lived 35 days really lived a few days longer, since the teliospores 
actually died between tests. When there was enough material, a lot 
which gave no germination in a test was retested twice more to insure 
accuracy. 
When the tests were concluded the teliospores on Ribes americanum 
were germinating rather strongly, although they had weakened per¬ 
ceptibly. Those on R . glandmosum were still germinating, but were 
rather weak and evidently approaching the limit of their viability. 
As in 1921 (16), some of the teliospores from R. nigrum were germinat¬ 
ing strongly, and, considering their age, relatively abundantly. In 
view of the results obtained in 1921, there seems to be no good reason 
for believing that these strongly germinating teliospores would lose 
their viability before winter set in. 
On the other hand, three lots of teliospores from Ribes uigrum had 
died about the first of October. It appears that the teliospores from 
R. rotundifolium may lose their viability rather quickly. However, 
those from the latter species, collected August 4, were borne on leaves 
which had both surfaces completely coated with dew at the time of 
collection. Partial germination had taken place, and the viability of 
the remaining teliospores was unusually low, as shown by tests made 
immediately after collection. The telial columns collected August 3 
on leaves of R. triste and R. glandulosum were probably quite old, 
because of a local drought which stopped telial production and 
germination (IS). 
Teliospores on naturally fallen leaves of Ribes nigrum, collected 
from the ground, lived 57 days when kept out doors. This indicates 
that infected leaves, even when lying on the ground, may be sources 
of pine infection for a prolonged period. It is well known that such 
leaves may be blown for some distance (17). These facts complicate 
the making of direct field observations upon the distance that sporidia 
may travel and cause pine infections. But such field observations 
are valuable in determining how far infection may extend, regardless 
of the manner, from Ribes to pines. 
Teliospores on Ribes nigrum, collected August 23 and stored in¬ 
doors, lived 49 days, while part of the same material kept out doors 
exposed to wind and rain gave 11 per cent germination after 70 
days. Another lot of material from R. nigrum, collected August 1 
and kept indoors, gave germination after 64 days. 
Early in January, 1924, teliospores from Ribes leaves which had 
been kept dry in folders were tested for viability by the floating 
method. The collections were as follows: 2 made in 1915; 3 in 1916; 
4 in 1919; 3 in 1920; 2 in 1921; 3 in 1922; 5 in 1923; and 4 in 1924 
(fresh material from the greenhouse). In most collections, persist¬ 
ing old promycelia were observed in some abundance, but no new 
germination of teliospores was observed after 24 and 48 hours, except 
in the 1924 material, in which the germination was very good within 
24 hours. 
