[Vor. 4 
102 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
ple block of each species of wood and their relative densities 
are not reported, it is with considerable hesitation that we 
would compare thereby the relative resistance of the various 
species of wood tested. Nevertheless, in the case of longleaf 
and shortleaf pines it shows that in some cases, at least, short- 
leaf is more resistant than longleaf. 
METHODS оғ EXPERIMENTATION 
Samples of wood of longleaf pine (Pinus palustris) and 
shortleaf pine (Pinus echinata) were secured from the Julius 
Seidel Lumber Co., St. Louis, and longleaf pine and loblolly 
pine (P. Taeda) from the John L. Roper Lumber Co., New 
Berne, N. C. The samples were numbered from 1 to 45. The 
cross-sections of 1-42 are shown in plates 10 and 11. Samples 
1-11 and 43-45 were P. echinata from southern Missouri, 
12-19 were P. palustris from Mississippi, 20-30 were P. 
Taeda from North Carolina, and 31-42 were P. palustris 
from North Carolina. The samples were selected in the lum- 
ber yards with only a cursory examination of the various 
physical factors to be investigated. In this way a wide range 
of these factors were obtained. 
Ж. o - n aum . 
аа 79 Each sample was cut into 
<< E Е Fa РИ culture blocks 1Ж1Х2 inches, 
4% A as shown in fig. 1. First, the 
CASCERN- Z\6 | end of each of the samples was 
E LX а 7 «| marked off into one-inch 
A squares, and each of these 
vlo'z % А Ya squares was labeled with a 
ыл ley la| letter, beginning alphabetieally 
e128 +5 2 (|| ав near the pith аз possible. 
oa KA " (In fig. 1 the circle between А 
оро 2 д апа С represents the pith.) 
ss 2 With this system of lettering 
B-Fuwi9 ж each letter represents a column 
Fig. 1. of culture blocks a certain dis- 
tance from the pith; thus, in the label M 1101, M represents 
the position of the column of culture blocks, 11 represents 
the number of the whole sample, and 1 the number of the first 
