Pilzkrankheiten der Pflanzen 
271 
form aufzufassen, als Hemmungsbildung, wie sie auch durch anderweitige 
ungünstige Beeinflussungen künstlich hervorgerufen werden kann. Da¬ 
neben tritt, als specifische Wirkung des Pilzes, eine Hypertrophie des 
Grundgewebes ein, die sich jedoch bei der mehrjährig-kranken Pflanze 
mehr und mehr wieder verliert. Lakon (Tharandt). 
GrlDDINGS, N. J., The Chestnut bark disease (W. Virginia Agr. Exp. 
Stat. Bull. 137: 209—225, figs. 1—12, March 1912). 
This is a popular review of the Chestnut bark disease issued for 
the benefit of the inhabitants of the state. The disease has been found 
at three points in West-Virginia. Lumbermans estimates of the Chestnut 
timber in the state average about 5 billion feet, with a stumpage value of 
about 15 billion dollare, hence the importance of controlling the further 
spread of the disease. C. J. Humphrey (Madison, Wise.). 
METCALF, H., Diseases of the Chestnut and other trees (Transact. 
Mass. Hort. Soc. 1912, Part I, 69—95). 
The paper is in the form of a lecture delivered before the Massa¬ 
chusetts Horticultural Society. In forest pathology we deal with trees 
under two cultural types: 1. trees in the forest; 2. shade, ornamental and 
park trees. The former problem is attacked along the lines of general 
forest sanitation, while to individual trees spraying and elaborate systems 
of pruning and wood surgery can be applied. 
After a brief general review of nursery and forest tree diseases, 
and their control, the author takes up a critical consideration of the 
chestnut bark disease, caused by Diaporthe parasitica Murrill. In 8 
years this fungus has caused not less than 25 million dollars loss of 
property. A description of the symptoms and general effect is given. 
The disease is limited to the genus Castanea , although the Japanese, 
Korean and Chinese varieties are decidly resistant. Castanopsis is im¬ 
mune. 
The author thinks the disease introduced from the Orient. The 
fungus is a virulent parasite and there is nothing to indicate that a tree 
with reduced vitality is more readily attacked than a perfectly healthy one. 
Efforts at controlling the epidemic take the form of limiting its 
spread by cutting out advance infections, inspection and destruction of 
diseased nursery stock, application of tree surgery to ornamental and 
orchard trees, tree medication through fertilization or direct chemotherapy, 
and by the breeding of resistant trees. 
C. J. Humphrey (Madison, Wise.). 
Pennsylvania Chestnut Tree Blight Commission, The Chestnut blight 
disease, means of identification, remedies suggested and 
need of cooperation to control and eradicate the blight (Bull. 
1, 9 pp., 1 map, 2 pi.; Oct. 1912). 
A brief popular review of the symptoms, development and spread 
of the disease is given, together with a map showing the present distri¬ 
bution in Pennsylvania. A loss of ten million dollars is estimated for 
the state. The dissemination of spores by birds, insects and the wind is 
discussed, and as infection only takes place through wounds, borers come 
