DEFECTS IN WOOD CAUSED BY SAPSTTCKERS. 57 
produced during the healing of sapsueker wounds, such as small 
sound stains, curly grain, and a form of bird's-eye. 
The earliest communication we have on this point is from Charles 
Eshorn, jr., of Medora, Ind. On May 27, 1892, he wrote to the 
Biological Survey as follows: 
[The sapsueker] ruins a great deal of valuable forest timber, namely, oak and hick- 
ory, by peeking holes. ... As the tree grows these places decay, which renders the 
timber unfit lor spokes, staves, etc. These birds are not very numerous, but it seems 
that each individual can do a great deal of mischief, and should the country be over- 
run with them they would be a great drawback to the timber business. 
The relation of sapsuckers to lumber was first studied by Dr. A. D. 
Hopkins while he was connected with the West Virginia Agricul- 
tural Experiment Station. He discovered that curly and bird's-eye 
wood are often caused by injuries to living trees by woodpeckers. 
Dr. Hopkins read a paper on the subject before section F of the 
American Association for the Advancement of Science, 1 and another 
before the American Forestry Association in August, 1894, and he 
spoke on the same subject at a meeting of the Biological Society of 
Washington March 25, 1902. Dr. Hopkins has generously turned 
over to the Biological Survey the manuscript and photographs 
illustrating the latter communication, in addition to his large col- 
lection of wood samples showing woodpecker work. This collection, 
augmented by material gathered by the writer in the field or exam- 
ined in various museums, forms the basis of this section of the 
bulletin. 
In his address on " Ornaments and blemishes in wood caused by 
insects and birds," 2 Dr. Hopkins says: 
Blemishes or defects appear in lumber and wood finish as discolored spots, checks, 
dark stains, resin deposits, pinholes, wormholes, etc., and in the trees as scars, decayed 
spots, and hollow trunks. 
Ornamental conditions appear in the lumber and inside finish and furniture as 
so-called bird's-eye, curly, burl, and wavy or satined effects and on the surface of 
the wood beneath the bark as artistic and curious carved and embossed work. 
Twenty or thirty years ago, when the choicest material could be selected from an 
abundant and cheap supply, blemishes were rarely seen, even in the cheaper finished 
products. Within recent years, however, the supply of choice lumber free from defects 
is becoming so scarce that none but the most expensive finished articles are entirely 
free from them. Indeed, it would be difficult to find a recently constructed public 
building or private residence which does not show in the natural wood finish one to 
many blemishes, the result of various causes. Most of them which are not natural 
conditions in the wood are caused primarily by insects, birds, mammals, and various 
other agencies which produce wounds in the cambium of the living tree. 
1 Hopkins, A. D., Some interesting conditions in wood resulting from the attack of insects and wood- 
peckers. Proc. Am. Assn. Adv. Sci. 1S94, p. 252 [abstract]. Excerpts from this paper were published 
by Dr. Hopkins under the title " The Relation of Insects and Birds to Present Forest Conditions, " in Garden 
and Forest, VII, 348 and 373, 1894. Its subject matter was brought before the Biological Society of 
Washington by Prof. C V. Riley. Dec. 15. ls>4, in a paper entitled "Some Interesting Results of In- 
juries to Trees;" and a review by H. C Hovey appeared in the Scientific American, LXXI, 163, 1894. 
s Meeting of Biol. Soc. Wash., Mar. 25, 1905. 
