MAY 27 19f)ft 
The Ohio V^aturalist, 
published by 
The Biological Club of the Ohio State University. 
Volume VIII. MAY. 1908. No. 7. 
TABLE OF CONTENTS. 
Dachnowski— Type and Variability in the Wood-increment of Acer Rubrum L. 343 
Hubbard —Stream Diversion near Lakeville. Ohio. 349 
Durrant— Description of New Mallophaga. Ill. . 355 
C'aknf.y and Brumback— The Deposit!) of Glass Sand at Toboso, 0. 358 
On the Death of William Ashbrook Kellerman. 361 
LIBRA 
NEW \< 
LOT AM 
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TYPE AND VARIABILITY IN THE ANNUAL WOOD- 
INCREMENT OF ACER RUBRUM L. 
Alfred Dachnowski. 
In all temperate zones, at least, trees form annually one 
layer of wood, which appears on a cross-section of a tree as a 
ring, more or less clearly defined. The rate at which the dia¬ 
meter and the area of any cross-section of the tree increases, can 
therefore be easily ascertained by measuring the width of the 
rings. To obtain direct evidence as to the relation of the rate 
of wood formation to the nature of the habitat, and to obtain 
information on the value of a biometric study in differentiating 
such habitats, statistical work has been carried out during the 
past winter of 1907-8. The work was done in connection with 
an inquiry on the toxic properties of bogwater and bogsoils, 
the data of which, correlated with this and other studies, will 
be brought out elsewhere in another paper. 
The purpose of the article here briefed is to call attention to 
the fact that statistical methods first used by Galton and now 
applied by Pearson (7), Davenport (4), Shull (8), and others to 
the more complicated questions in variation and heredity, may 
be of service also in Forestry problems as well as in questions 
of Ecology. 
About 25 miles east of Columbus occurs an extensive lake, 
approximately ten miles long and one mile wide, known as Buck¬ 
eye Lake. Near the northern bank, and midway between the 
small towns of Lakeside and Avondale is a bog-island very near¬ 
ly one-tenth the dimensions of the lake. Soundings made to 
determine the character of the peat gave 30 to 40 feet as the 
depth of the island. Its vegetation presents two well-marked 
zones,—a central one consisting of Sphagnum, Carex, Erio- 
phorum, Oxycoccus, Drosera, Rhus vemix, Aronia nigra, 
and others, and a marginal zone which includes besides several 
species of Salix, Alnus incana, A. rugosa, Ilex verticillata, Comus 
