116 
peas belonging to the Plant Breeding Institute at Svalöv. 
A great many of the plants, in some varieties every 
plant in the parcel, were at this time wilted and partly 
dried up. Many seeds in the pods were still immature, 
and were clothed with a thick layer of mould belonging 
to the genera Aspergillus , Pénicillium and Cladosporium. 
The base of the stem often showed a dark reddish co- 
lour. The following account of the weather conditions 
and of the early signs of the disease was given me 
while visiting the place. The early part of the summer 
had been exceptionally dry and windy, which had had 
a decidedly injurious effect on the germination and on 
the early development of the peas. About midsummer 
enormous masses of thrips had been seen on the peas, 
and the attack of these insects had apparently weake- 
ned the plants to some extent. In late summer and in 
autumn rainy weather predominated. In the former part 
of July some plants were seen to droop and become yel- 
low. More and more of the plants wilted. The trouble 
commenced at the neck of the root, where dark-brown 
streaks appered which slowly spread up the stem. Growth 
ceased as soon as the plant showed signs of the disease, 
and the youngest leaves and pods were the first organs to 
wilt. The varieties worst attacked were »Non plus Ultra» 
and certain strains from »Stensärt» ; those least attacked 
were »Gradus», »Non pareil» and »Champion of England». 
From the material brought to the laboratory cross- 
sections were made, and these were examined under the 
microscope. The base of the stem was found to be 
traversed by branched hyphae, which were especially 
abundant in the bark layer. Mycelium was also abun- 
dantly found in the cracks and fissures of the stem, and 
could be traced ut least 20 cm. upwards. 
In isolating the fungi pieces of the stem were ste- 
rilized on the outside and put into damp chambers. 
Transfers were then made to the tubes containing the 
