300 
heart-wood except in very old trees. It finishes with a very 
smooth surface in whichever way it is worked, hence its value for 
carving and turnery. The wood is also very popular for the 
manufacture of instruments and is widely used for T squares 
and set squares. Another use for the wood is the manufacture of 
camera shutters and for this purpose it is stained black. Treated 
in a similar way it is sometimes used as a substitute for ebony in 
the manufacture of cabinets and small fancy articles. The 
wood, however, requires very careful seasoning, otherwise it 
twists. As a rule persons who have a few trees to dispose of 
would do better by offering them to firms who specialise in 
cameras or scientific instruments rather than to a local timber 
merchant. Ww. D 
The Douglas Fir Chermes.*—During the last few years 
foresters have been alarmed at the rapid spread of the Douglas 
Fir Chermes (Chermes cooleyi), and in view of the fact that closely 
allied insects make it difficult to cultivate certain silver an 
the Weymouth pine, the Forestry Commission decided to 
investigate thoroughly the life-history of the Douglas Fir Chermes, 
in order that an idea could be formed of the injury it is likely to 
cause. The work was entrusted to Mr. R. N. Chrystal, B.Sc., 
under the direction of Dr. Munro, the Commission’s Entomologist, 
and by arrangement with the Director the laboratory work was 
upon his investigations with previous knowledge of his subject 
as he has undertaken similar research work in Stanley Park, 
Vancouver, for the Canadian Entomological Service. The work 
was commenced in November and was continued throughout 
1921 and the summer of 1922. The result of the 1921 work has 
just been published in bulletin form by the Forestry Commission, 
and both they and the author are to be congratulated upon the 
production of a very clear and well illustrated contribution to 
the life history of Chermes cooley: in Britain compared with 
Forestry Commission Bulletin, No. 4, The Douglas Fir Chermes 
(Chermes cooleyi), 1922, price 2s. net. (Obtainable from H.M. Stationery 
Office, Imperial House, Kingsway, W.C. 2). 
