Slugs as Mycophagists. A. H. R. Buller. 283 
CONCLUSIONS. 
(rt) The successful experiments with Phallus impudicus, 
Russula heterophylla and R. nigricans, described above, clearly 
show that the fruit-bodies of these fungi, under certain con- 
ditions in the open, attract Limax maximus from a distance of 
at least Io to 21 ft. 
(2) Having regard to the well-known short-sightedness of 
slugs, to the fact that slugs find their food at night, and to the 
sensitiveness of Limax maximus to mustard gas when diluted 
to one part in ten million, my observations and experiments 
lead me to suppose that fungus-eating slugs react at a distance 
to the odours given off by fleshy fungi, and that in woods and 
gardens they find the fungi upon which they feed by their sense 
of smell. 
(3) The chemotaxis of slugs, not merely for fungi but also 
for garden produce such as lettuce and cabbage, is a subject 
concerning which our information is still very meagre, but 
which is very amenable to experimental treatment. If the 
chemotaxis of slugs were sufficiently elucidated, we might per- 
haps be able to devise much more efficient means for protecting 
our gardens from the ravages of slugs than any at present known. 
ON THE SYMPTOMS OF WILTING OF 
MICHAELMAS DAISIES PRODUCED BY 
A TOXIN SECRETED BY A CEPHALO- 
SPORIUM. 
By W. J. Dowson, M.A., F.L.S., Royal Horticultural 
Society's Garden, Wisley, Ripley, Surrey. 
The investigation of a serious and widespread wilt disease of 
Michaelmas Daisies undertaken at Wisley in the autumn of 
1920 and not yet completed has already led to definite results 
concerning the action of the parasitic fungus involved. 
In the present paper it is intended to give only an account of 
the experiments which led to the conclusion that the symptoms 
of the disease are due to the secretion of a toxic substance by 
the parasite. The complete account of the investigation of the 
disease including the morphology of the parasite is left over for 
a further paper. In recent literature dealing with wilt diseases 
due to species of Fusarium investigators have suspected that 
the actual symptoms of wilt are due, not so much to the clogging 
of the vessels and tracheids of the xylem thereby causing an 
