346 THE CONIFERS (GYMNOSPERMS) — FORESTS 
STUDENT REPORT 
Needles 
Single 
Alternate 
Needles 
Scale-like 
Needles 
in Bundles 
Cones 
Large 
Cones 
Small 
Hemlock . 
White Pine 
Larch . . 
Cedar . . 
Spruce . . 
Etc. . . . 
LABORATORY WORK 
In the laboratory examine a cross section of the stem to see the dif¬ 
ference in the cells grown in the early and in the late part of a season. 
Note the pith and medullary rays. If specimens are available, examine 
sections of wood from different trees. Make a collection of the woods 
found in the vicinity. Examine scales from staminate and carpellate 
strobili. With the microscope examine pollen of pine. Draw and 
describe all. 
294. Economic Importance. — The value of the gym- 
nosperms can scarcely be overestimated. Most of the 
trees are sawed into lumber for building purposes, but 
some of them are used in their natural form for telegraph 
poles, masts of ships, and timbers of mines. Wood pulp, 
from which most of our paper is made, is produced from 
small spruce trees. The by-products of this group of 
trees are of great value. From the pine come tar, pitch, 
turpentine, and resin, while the bark of the hemlock was 
formerly extensively used in tanning leather. 
295. Forestry. — By forestry we mean the raising of 
repeated crops of timber on land unsuited for agriculture. 
An additional meaning that has come to be attached to it is 
the proper use of forest crops. This definition will make 
it plain that it is quite separate from agriculture, which is 
concerned principally with the crops which feed man or his 
animals or which furnish him material for clothing. It is 
