THE SYCAMORE SOOTY BARK FUNGUS 13
fungus; this I will leave to Dr. Gregory, who is more competent to
do so than I. He has collaborated most ardently in our investiga-
tions since I first introduced him to the disease. This introduction
took place late in the evening after he had attended the Club's
Fungus Foray and I can truthfully say that looking for the
proverbial negro in a coal cellar was as nothing compared with
looking for this black-spored fungus in the darkness. I am sure
that he will shed more light on the matter than was present on that
memorable occasion!
The Sycamore Sooty Bark
Fungus (Cryptostroma corticale)
BY P. H. GREGORY
Rothamsted Experimental Station, Harpenden, Herts.
[Read 27 January 1951]
The disease of Sycamore (Acer pseudoplatanus) which we are
calling "Sooty bark" was first observed in Wanstead Park,
Essex, in 1945, by S. Waller, who published the first account of its
occurrence (Essex Naturalist, 28, 136-8, 1949). Both the disease
and the fungus exhibit several curious features. Perhaps not the
least remarkable is that diseased trees, which are conspicuous and
widespread in the London area, have apparently never been re-
ported from anywhere except by people who have already heard
of the disease directly or indirectly from Mr. Waller. Two further
accounts have now been published, a preliminary note on the
disease by Gregory, Peace, and Waller (Nature, Lond,, 164, 275,
1949), and a more detailed account of the fungus itself by Gregory
and Waller (Trans. Brit. mycol. Soc, 34, 579-97, 1950).
The identification of the fungus was not easy. The usual keys to
the Fungi imperfectiled us to the genus Torula, for various reasons
an impossible genus for our fungus. Eventually help from the
Ministry of Agriculture Plant Pathology Laboratory, Harpenden;
the Commonwealth Mycological Institute, Kew; and the New
York Botanic Garden, which kindly lent a type specimen for com-
parison, established that the fungus on sycamore is, at least
morphologically, the same as Coniosporium corticale Ellis and