WHITE-PINE BLISTER RUST. 39 
In April, 1918, Dosdall tested in distilled water (in hanging-drop 
cultures) the viability of seciospores produced in 1917 (29). On 
April 19, 1918, a dead white-pine branch bearing a canker which 
had fruited in 1917 was collected at Rush Lake, Minn. While new 
secia were just beginning to break open on other cankers at this 
time, the spores tested were not new ones, as they were dug from the 
bottoms of 1917 cavities after scraping off the outer exposed spores. 
Nor could there have been new secia pushing up beneath the old 
ones, as the branch was dead. It was found that from 1 to 2 per 
cent of the spores germinated in distilled water, each spore producing 
from 3 to 5 germ tubes. It is barely possible that these spores 
were from an abnormally late secium (179) and therefore were not so 
old as Dosdall supposed them to be. Even so, they must have been 
approximately 6 months old. 
This experiment of Dosdall has been repeated. A dead branch 
bearing secia of 1918 was collected at Kittery Point, Me., on Febru- 
ary 25, 1919, and taken to Washington, D. C. Taylor tested the 
seciospores by hanging-drop cultures in tap water, but no germina- 
tion of the spores could be demonstrated. Spores of other fungi 
were present and did germinate. 
York 20 collected a specimen of diseased white pine bearing newly 
formed secia on April 30, 1918. This was put in a paper bag and left 
in the laboratory away from direct sunlight until October 5, 1918. 
He then broke open a still unbroken secium which had not pushed 
through the outer bark and made cultures of the spores. He got 
some germination in tap water under these condition 157 days after 
collection of the material. The spores were still yellow when the 
test was made. Spores from secia which had broken open did not 
germinate. 
During the season of 1918, Pennington 21 found that in the Adiron- 
dacks the seciospores remained viable for at least four weeks after 
being removed from the secia and stored in a dry place. The same 
season, York found that in the White Mountains seciospores from 
blisters in cankers cut from the tree and kept in the shade out of 
doors remained viable for 75 days, as shown by tap-water cultures 
and inoculations on Ribes leaves. 
In 1919, Pennington 21 found that seciospores, whether brought 
into the laboratory or left in the field soon lost their viability, less 
than 1 in 400 germinating after three weeks from the breaking open 
of the secium producing them. Tests upon the viability of seciospores 
after they had been exposed to direct sunlight showed a decrease of 
50 to 75 per cent in viability after three hours' exposure. After 
an exposure of eight hours, some of the seciospores (1 in 1,500 or 
2,000) were still viable. 
20 York, H. H. Op. clt. 
2i Pennington, L. H. Op. cit. 
