pable of protecting themselves from enemies of any
description. For the first three days after they are hatched the female
spends much of her time in brooding them, and, when she is thus
occupied, the male sometimes brings food to her, which she proceeds to
distribute or swallows. But all the young cannot be fed, neither are
they ready to be fed, at the same moment; and the parents have besides
to find food for themselves, and the nest has to be cleaned--all of
which necessitates the young being exposed to the elements at frequent
intervals. Now it is impossible to observe the instinctive routine of
the parents, when the young need attention, without being impressed with
the conative aspect of their behaviour. Why, we ask, are the movements
of the female so brisk; why does she seek food and clean the nest so
hurriedly; why, if her instinctive routine is interrupted, do her
actions and her attitude betray such bewilderment? I take it that the
only answer we can give to these questions is that the part of her
inherited nature which predominates just at this particular time is to
brood. But why is brooding of such importance? Partly to maintain the
young at the proper temperature, and thereby to induce sleep--and sleep
for offspring newly hatched is as important as food--and partly to
protect them from the risk of exposure to extremes of temperature. This
latter danger is no imaginary one. Examine a young bird that has
recently left the egg; observe its nakedness; and consider what it has
to withstand--a temperature that may rise to 70 deg. F. or may fall to 40
deg. F., the tropical rain of a thunderstorm or the persistent drizzle of
many hours' duration, the scorching effect of a summer sun or the
chilling effect of a cold north-easterly wind, and, constantly, the
sudden change of temperature each time that the parent leaves the nest.
One marvels that it ever does survive; one marvels at the evolution of a
constitution sufficiently elastic to withstand such changes. But,
however much the constitution may give us cause to wonder, it is clear
that much depends upon the parents. A slight inefficiency of the
instinctive response which the presence of the young evokes, a little
slowness in searching for food or sluggishness in returning to the nest,
might lead to exposure and prove fatal. And, however much is demanded of
the parents, it is clear that much also depends upon the relationships
in the external environment; for no ma