218 A TEXT-BOOK OF BOTANY 
it is packed nutritive tissue (often called endosperm), which 
is the female gametophyte; and outside of that there is 
found the bony seed-coat (testa). In 
this condition of suspended animation 
the embryo may continue for a long 
time, certainly until the next season, 
Fre. 206. Section of perhaps for many seasons. When the 
a pine seed, showing 7 ERS 
embryo (young spo- seed comes into favorable conditions 
rophyte) embedded and “awakens,” the embryo escapes 
in endosperm (fe- 
male gametophyte), and grows into the pine-tree. This 
salad ee ny awakening of the seed is usually called 
its “germination,” but it must not be 
confused with the germination of spores and odspores. 
The “germination” of the seed is merely the resumption 
of growth by the embryo and its escape from the seed. 
In seed-plants, therefore, there are two distinct periods in 
the growth of the sporophyte, the period within the seed 
(when it is called an embryo), and the period outside of 
the seed; and these two periods may be separated from 
one another by a long period of time. For an account of 
seed germination see Chapter V. 
128. Timber from Conifers.—The conifers are the most 
important source of timber in the United States, yielding 
at least three-fourths of our supply. They are usually 
called “soft woods” in distinction from the so-called 
“hard woods,” such as oak; but there are soft and hard 
woods in both groups. The United States is notable for its 
variety of pines, broadly grouped into the soft white pine 
and the hard yellow pines. Our principal supplies come 
from the white pine forests about the Great Lakes and the 
yellow pine forests of the Southern States; but the forests 
of the former region have been cut over so ruthlessly for so 
long a time that the supply of white pine is diminishing. 
A few years ago the white pine furnished nearly one-third 
of all the timber produced by the United States. It is very 
