THE SIGNIFICANCE OF CERTAIN VARIATIONS IN THE 

 ANATOMICAL STRUCTURE OF WOOD 



By R. p. Prichard^ and I. W. Bailey^ 



In the following pages are siinimarized the restilts of one of a 

 series of investigations that have been undertaken at the Bussey 

 Institution in the study of plant tissues and cells, their compara- 

 tive structure, relative conservatism, and behavior under the 

 influences of various modifying factors. The investigation deals 

 with the variation in size of the principal woody elements (fibers 

 and vessel-segments) in various parts of the stem of a single species, 

 the common Shagbark hickory, Carya ovata (Mill) K. Koch. 



Tables and Other Data 



Specimens of wood were secured from three different trees, a 

 mature virgin-forest tree from West Virginia, a second-growth 

 tree of seedling origin from eastern Massachusetts, and a sprout- 

 hardwood from near Syracuse, New York. Sections of the 

 selected trees were cut at various heights from the groimd. Blocks 

 were cut radially from each section, and chips were taken from 

 every fifth ring. These chips were macerated by treating with a 

 5 per cent solution of equal parts of chromic and nitric acid, and 

 the cells were separated by shaking with water and glass beads. 

 Measurements were made with a micrometer eyepiece, 50 of fiber 

 lengths and 20 of vessel-segment lengths. To obtain the diameters 

 of the vessels microscopic sHdes were made from different 

 portions of each section, and measurements were taken from 

 these sHdes with a micrometer eyepiece. 



The results are shown in the following tables and diagram : 



Length of Fibers at Different Ages of a Tree 



Table I. — Carya ovata (sprout), Table II. — Carya ovata (seedling), 



60 annual rings, cross section 1 foot 65 annual rings, cross section 2 feet 



from the ground. Specimen from from the ground. Specimen from 



near Syracuse, New York. near Boston, Massachusetts. 



Fiber Lengths Fiber Lengths 



Annual Millimeters Annual Millimeters 



Rings Max. Min. Ave. Rings Max. Min. Ave. 



5 1 34 .62 .89 1 .98 .54 .73 



10 1 60 .80 1.11 5 1.10 .66 .90 



15 1 66 .56 1.21 10 1.30 .66 1.Q2 



1 Assistant Professor of Forest Products, Syracuse University. 

 ' Assistant Professor of Forestry, Bussey Institution for Research in Ap- 

 plied Biology. 



662 



