46 
SOME OBSERVATIONS ON PUCCINIA BISTORTA. 
Whilst at Yeaden, near Leeds, on May 14th, I also found the same 
iEcidium, and this was confined to Conopodium that grew 
amongst Bistort ; no trace of the fungus could I find elsewhere, 
although the host was not uncommon. 
For the purpose of testing whether there was any connection 
between the two forms I applied teleutospores of the Puccinia to 
Conopodium denudatum on May 9th. A result was obtained on 
May 21st, on which date a discoloured swelling was observable near 
the base of the stem, and on this secidiospores appeared on May 
30th. 
On May 9th I applied germinating secidiospores from Conopo- 
dium to several plants of the same species, but not the slightest 
result followed. The aecidiospores artificially produced were in a 
state of germination on June 1st, and on that date were applied 
to the leaves of Polygonum Bistorta, P. Brunoni, P. persicaria , and 
P. aviculare. The first sign of a result was on June 10th, when 
yellowish spots began to appear on the upper surface of the leaves 
of P. Bistorta , and on July 16th the rufous sori of uredospores 
were conspicuous on the under surface, immediately below the 
spots. No result ensued on P. Brunoni , P. persicaria , or P. 
aviculare. 
With the uredospores thus produced I infected P. Bistorta on 
June 22nd. Yellowish spots appeared on the upper surface on 
June 30th, and uredospores were evident on July 3rd. These 
were applied to 'other plants of Bistort on July 12th, and re- 
produced themselves on July 23rd. On July 17th germinating 
uredospores were applied to the leaves of Polygonum viviparum 
and P. Bistorta , but not the slightest result ensued on the former, 
while uredospores were copiously developed on the latter by 
August 4th. 
In every case the uredospores were succeeded by teleutospores, 
which invariably appeared in the same spot as the uredospores eight 
or ten days after the latter were mature. 
A similar series of cultures were conducted, commencing with 
jEcidiospores, collected at Hebden Bridge, on Conopodium denu- 
datum. These were in an active state of germination on May 9th, 
and applied to leaves of Bistort. The first sorus of uredospores 
appeared on May 22nd, and teleutospores on June 1st. 
Uredospores produced from the last mentioned applied to Bistort, 
on May 28th, were reproduced by June 8th, the teleutospores 
beginning to appear on June 18th. 
Uredospores were applied to other Bistort leaves on June 19th, 
and the rufous sori of uredospores appeared on June 30th. On 
July 10th these were again applied to the leaves of another Bistort 
plant, and the first sorus of uredospores was evident on July 21st, 
and teleutospores on August 6th. 
Many times during the summer the teleutospores were placed in 
water, but in not a single instance did I observe any attempt at 
germination. 
