THE FORMATION OF FORESTS 93 
The choice of species to plant or to favor in the 
improvement of forests is extremely important, and 
should always receive much consideration. The se- 
lection of the wrong species means labor lost and dis- 
appointment after long years of waiting. It is said 
that a tree may thrive and give great promise in 
youth, and then later die and disappoint one, or vice 
versa. In general, however, it is safe to assume that 
if a tree does well in youth, which is, of course, its 
tenderest age, the chances are favorable for good 
attergrowth. It is, of course, safer to plant indige- 
nous species, or those exotics which are so well known 
that there can be no mistake. It is not wise, however, 
to cling tenaciously to those species which are native, 
when it is positively known that certain foreign spe- 
cies will serve our purposes better. The writer has 
known of persons who considered it unpatriotic to 
use foreign species. The white-pine, Douglas-fir, 
red-oak, locust, and tulip-tree are more exten- 
sively planted in Europe to-day than in their native 
country. 
It is safer to plant the European spruce (Picea 
excelsa) than our native northeastern spruces. Our 
native spruces are difficult to distinguish from one 
another. Botanists are constantly disagreeing in ref- 
erence to their identity. Still more difficult would it 
be for the seed collector to determine. Our spruces 
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