5G WOODPECKERS IN RELATION TO TREES. 
Boraford, B. Yellow-bellied Woodpecker. Forest and Stream, XX, 124, 1883. 
BOUGH, \l. I'». 1 1 and hook of the Trees of the Northern States and Canada. Lowville, 
N. Y., L907. Several photographs of trees show Bapsucker work. 
Boy, P. R. ■ Dendrocopua varius, Linn. Yellow-bellied Woodpecker.. Notes on 
the Ornithology of Wisconsin. Trans. Wis. State Agric. Soc, II, 356, 1852. 
Boy, P. R. Tito Sapsucker. Trans,. 111. State Hort. Soc, V, 730-735, [1861-1864] 
L865. 
Jones, Lynds. Sphyrapicus varius (Linn.). Yellow-bellied Bapsucker. The Birds 
of <>hio. Ohio Acad. Sci. Special Papers, No. 6, pp. 113-114, 1903. 
Ki:w\i;i). \\ II. January Occurrence of the Sapsucker in Bmoklino, Mass. Auk* 
XII, 301-302, IS!).,. 
MeRRIAM, C. BART. SphyrapicUS VarittS. Yellow-bellied Woodpecker. Remarks 
on some of the Birds of Lewis County, northern New York. Hull. Nuttall Orn. 
Club, IV, 1-6, 1879. 
M ERRILL, .1 . ( '. Sphyrapicus thyroideus. Notes on the Birds of Fort Klamath, Oregon. 
Auk, V, 255, 1888. . 
Moore, N. B. ( >bservations on some Birds seen near Nassau, New Providence, in the 
Bahama Islands. Proc. Bost. Soc. Nat. Hist., XIX, 245, 1878. 
Morris, C. II. Winter Notes on the Yellow-bellied Sapsucker (Sphyrapicus varius). 
Wilson Bull. XII, 56-57, 1905. 
Purdy, J. B. The Red-headed and other Woodpeckers in Michigan in winter. Auk, 
XVII, 174, 1900. 
Thompson, Charles S. The Woodpeckers of the Upper Salinas Valley. Condor, 
II, 52-55, 1900. 
Thompson, J. M. The Sapsucker. Appleton's Journal, VIII, 631, 1872. 
Todd, W. E. Clyde. Sphyrapicus varius. The Birds of Erie and Presque Isle, Erie 
County, Pennsylvania. Annals Carnegie Museum, II, 559, 1904. 
Warren, B. H. Sphyrapicus varius. Yellow-bellied Sapsucker. Report on the 
Birds of Pennsylvania. Ed. 2, pp. 168-170, 1890. 
Weed, C M., and Dearborn, Ned. The Yellow-bellied Woodpecker or true Sap- 
sucker. Birds in their Relations to Man. Pp. 189-191, 1903. 
WRIGHT, M. 0. Yellow-bellied Sapsucker: Sphyrapicus varius. Birdcraft, pp. 
198-199, 1897. 
EFFECTS OF SAPSUCKER WORK ON LUMBER AND FINISHED 
WOOD PRODUCTS. 
INTRODUCTION. 
Those relations of sapsuckers to trees »which are detrimental to 
man's interest are by no means confined to the external disfiguration, 
the weakening, or killing of trees. Indeed in the aggregate Bap- 
suckers inflict much greater financial loss by rendering defective the 
wood of the far larger number of trees which they work upon mod- 
erately but do not kill. Blemishes, reducing the value, appear in 
the Lumber from such trees and in the various articles into which it 
is manufactured. 
These defects consist of distortion of the grain, formation of 
knotty growths and cavities in the wood, extensive staining, fat 
streaks, resin deposits, and other blemishes. All of them result from 
injuries t<> the cambium, their variety being due to differences in 
the healing. Besides blemishes, ornamental effects are sometimes 
