Heart Rot of Ptseroxylon utile (Sneezewood) . 
22B 
removal of the possible sources of infection. Wherever it is intended to 
conserve forest areas, a careful search should be made for all trees infected 
with this fungus, and they should be promptly removed. This is the more 
important since, as already stated, in South Africa Fomes rimosiis does not 
limit itself to Ptasroxylon utile, but attacks a large number of trees belonging 
to different orders. 
The presence of the sporophores of the fungus on a tree is evidence of 
the presence of heart rot and of the necessity of removing the tree. Sj^oro- 
phores on trees should be removed wherever found. 
The practice of leaving uncut, trees affected with heart rot is wrong from 
the standpoint of proper forest sanitation, for it merely enables the causal 
fungus to develop its fructifications and exposes the coming generation to a 
continuous danger of becoming infected as soon as they have developed 
heart wood and the opportunity offers itself. Fomes rimosus is not known 
to form new fructifications after the attacked tree is dead, and a proper 
look-out for and the destruction of living diseased trees as well as the 
sporophores of the fungus should go a long way towards lessening infection 
in the forests. 
The foregoing would appear to be the most practical methods for con- 
trolling this disease in large forests. On a small scale it may perhaps be 
necessary to give attention to individual trees ; assist the natural pruning 
tendency of the tree and trim all wounds prior to painting them over with 
some disinfectant. The disinfectant should have sufficient penetrating power 
to infiltrate into the wood for some considerable distance. Coal-tar creosote 
heated up until thoroughly liquid will be found as good as any. The 
disinfecting is especially advisable where the wounds are large. 
Humphrey and Fleming * have recently published an interesting paper 
on the toxicity to fungi of oils and salts, and particularly those used in wood 
preservation. In their research they included two wood-destroying fungi — 
Fomes annosus, Fr., and Fomes pinicola (Sw.) Fr. They find the preservatives 
used act in a considerably different manner on these two fungi and the 
former to be as a rule more resistant. 
Mention should here also be made of a recent paper by Howef on the 
effects of various dressings on pruning wounds of fruit trees. The author 
found untreated wounds to heal more rapidly, and on peach trees the 
substances experimented with caused ao mueli injury that the author holds 
wounds on peach trees should never be treated with any of them. The 
author's conclusions are that there is nothing to show that it is worth while 
* Humphrey, C. J., &Fleming-, K. M., " The Toxicity to Fungi of Various Oils and 
Salts, particularly those used in Wood Preservation." U.S.A. Dept. of Agriculture, 
Bureau of Plant Industry, Bull. 227, 1915. 
t Howe, G. H., " Effect of Various Dressings on Pruning Wounds of Fruit Trees," 
New York Agric. Exp. Station (General), Bull. No. 396, 1915. 
