Birds’ Nests 
to the suitability of this or that sort of timber 
or furniture for their dwellings, and observa- 
tions upon it thus increase our acquaintance 
with the scope of ideas and habits characteristic 
of each species of bird.’’ 
A nest is ordinarily in perfect condition only 
for a few days after its completion. The incu- 
bation of the mother bird, the pressure of the 
chicks, as they develop, and the weight of the 
old birds perching on the edge, all tend to 
flatten and otherwise distort its original and 
ideal shape, especially in the more delicate 
sorts. Yet, oftentimes, it is not thus impaired 
to an appreciable extent; and, in case it is, 
a slow and careful inward pressure of the 
upper part will usually restore it almost to 
its normal form. But, if not taken before it 
is abandoned by the birds, it should be se- 
cured as quickly as possible thereafter; since, 
from exposure to the weather, it soon begins 
to disintegrate. Nor is the study of the nest of 
any species complete when a single specimen 
has been obtained, and its characteristics have 
been learned ; for even the same species will 
sometimes show curious differences ; as, for ex- 
ample—to mention two of the most familiar in- 
stances—the barn swallow, withits two distinct 
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