1896, } Purposes of Ethno-Botany. 151] 
forated. Some cells containing starch are also intermingled 
with these tracheids. In an annual layer of vigorous growth 
large bundles or masses of hard, dense fibers are seen just 
out of the concentric circles of ducts, and when fully formed 
extend through the outer part of the layer. These fibers 
vary in diameter from .006 to .0075 of aninch. The medul- 
lary rays run through the bundles and at frequent intervals 
are intersected by cells running parallel to the axis of the 
tree, thus dividing a mass of hard fibers into small rectangles. 
Such a detailed description coincides with the structure of the 
white oak, and after applying further tests we can rest assured 
that the wood is from one of the most valuable of our forest 
trees, 
If the study of the microscopic structure leads to no defi- 
nite conclusion as to the nature of the wood, then we 
might have recourse to other methods. (1) The specific 
gravity of the specimen can be readily calculated whether the 
Wood is heavier or lighter than water. A piece of wood 
Species of tree from which the wood was taken. (3) The 
Weight of the wood per cubic foot in pounds, and its fuel value 
We ha: 
ve now seven important facts concerning our piece 
of wood: 
I. Its geographical habitat. 
2. Its specific gravity. 
3- Its microscopical structure. 
4 Its fuel value. 
5. 7 resistance to transverse strain and compression. 
" -'S weight in pounds per cubic foot. 
7 Its ash, 2 J 
. . fan judge as to the past meteorological conditions by 
. .-*aMination of the annual rings of wood, but the difficulty 
Sto determ; 
in 
collect Hazzard collection, the year in which the wood was 
site: whether at once or after the piece had lain on the 
Valuabj for Some time. We have, however, in the wood a 
© indication as to the years of drought and excesses of 
