Cephalosporium wilt of Michaelmas Daisies. W. J. Dowson. 285 
was filled with boiled tap water, and into both were inserted 
vigorous green shoots of Michaelmas Daisies. The mouth of 
each bottle was lightly plugged with cotton wool to keep out 
dust and to lessen evaporation. All the bottles with their 
shoots were placed side by side close up to a window. After 
three days some of the leaves of the shoots in the filtered culture 
fluid became mottled with paler patches which soon spread and 
involved the whole surface of the leaves. More leaves became 
mottled and paler, until on the seventh day nearly all the leaves 
were bright yellow, shrivelled and dry. The stem which bore 
them also turned yellow. 
(These symptoms of mottling, paling, and yellowing were 
also observed in inoculation experiments with Cephalosporium.) 
The controls in water remained green and turgid until the 
tenth day when loss of turgor and shrivelling commenced, but 
no yellowing. 
In another series of experiments the filtered fluid was placed 
in a dialyser of gold-beater’s skin suspended in a small beaker 
of boiled tap water. After three days the water in the beaker 
outside the dialyser became slightly brown in colour and into 
this were inserted, as before, green healthy shoots of Michaelmas 
Daisies. Controls in which the filtered culture fluid was replaced 
by boiled tap water in the dialyser were also set up. The shoots 
in these remained as before quite green and turgid for ten days, 
but those in the dialysed liquid presented mottled leaves after 
two to three days and at the end of six nearly all were bright 
yellow and shrivelled. 
The effect was more marked and more rapid with the filtered 
and dialysed liquid. In one of the experiments with the filtered 
and dialysed liquid, green shoots of the resistant variety ‘“Gladys 
Donellan”’ were used to see if this plant behaved towards the 
toxic substance in a different way than did the susceptible 
varieties. 
The shoot was affected in the same way and in the same time 
as any other variety tried, thus indicating that “Gladys 
Donellan”’ is resistant to the fungus but not to the toxin. 
Eventually as this experiment and inoculations showed “‘ Gladys 
Donellan” succumbs as do other varieties of Novae Belgii and 
Novae Anglii, but takes longer over the process. Or, to put it 
in another way the mycelium cannot grow so quickly in the 
wood of ‘‘Gladys Donellan” as in other varieties, and therefore 
produces less toxin in a given time. 
The symptoms of wilting noted in the above experiments 
were repeated almost exactly when Michaelmas Daisy plants 
were inoculated with the mycelium of the fungus. The rapidity 
with which the effect was produced indicated the crystalloid 
M.S. 19 
