SCIENTIFIC COMMITTEE, JUNE 27. 
xcvii 
Peridcr7nimn pini to Sejiccio vulgaris. Once, and once only, did I suc- 
ceed in producing the uredo on the last-named plant. My non-success I 
attributed to some error in manipulation, and, as I was engaged with 
other species, I did not follow the research up. Dr. Klebahn, of Ham- 
burg, however, set about the problem, and soon cleared the matter up. 
He showed that the species of Coleosporium had their jecidiospores on 
Pinus sylvestris, and not C. scnecionis alone. The species on Tussilago 
Farfara, which is exceedingly common all over England, was one of the 
forms to which Dr. Klebahn directed his attention, and he gave the above 
name to its aBcidiospores. The specimens sent herewith were produced 
by artificial culture. On October IG, 1898, a leaf of Coltsfoot, with the 
teleutospores of Coleosporium Tussilaginis abundantly upon it, was 
fastened upon a young Pinus sylvestris ; on February 20 suspicious spots 
began to show, but it was not until April 22 that an abundant develop- 
ment of the Peridermium was observed. On that date the Coltsfoot leaf 
was still attached to the Fir, and the most abundant development of 
Peridermium was seen to be immediately beneath it. As this experiment 
was performed some three miles from my house, the plants were not 
visited so often as they otherwise would have been. On April 25 two 
young plants of Tussilago Farfara were infected with the above ascidio- 
spores, and on May 18 each was found to be abundantly affected with the 
uredo of Coleosporium Tussilaginis ; they were gathered, and are also 
sent herewith. I have to thank Mr. Walter Scott, of the Golden Ball 
Nurseries, for the material employed in these cultures, and Mr. Rodgers 
for his assistance in looking after the plants." Experiment No. 1,243 : 
— Coleosporium Tussilaginis placed on a young plant of Pinus sylvestris 
(infecting) : Material wired on to the tree October 16, 1898 ; Spermogonia 
observed February 20 ; Peridermium Plowrighti abundantly produced 
and fully developed April 22, 1898. Experiments 1,264, 1,265 :— Two 
young plants of Tussilago Farfara, infected on April 25, 1899, with 
^ecidiospores of Peridermium Plowrighti from Experiment 1,243 ; perfect 
uredo gathered May 15. 
Scientific Committee, June 27, 1899. 
Dr. M. T. Masters, F.R.S., in the Chair ; four other members present, and 
Mr. H. J. Webber, of the Agricultural Department, Washington, 
U.S.A. 
A Monstrous Cattleya. — Dr. Masters observed that the specimen 
brought to the last meeting was characterised by having a sepal in a 
petaloid condition ; but the same feature occurred in three flowers on the 
spike. 
A Malformed Catasetum rostrianum. — A spray bearing two flowers, 
with the lateral petals having the characters of the lip, was sent by Sir 
Trevor Lawrence. 
Diseased Carnations. — Specimens were sent by Mrs. E. Mackay, which 
proved to be attacked both by bacteria and Puccinia dianthi. Mr. Webber 
observed that the disease known as bacteriosis is now generally regarded 
