194 
NESTS AND EGGS OE 
persons of sense and education, and amply recompensed. Here they be- 
come remarkably unsuspicious, nesting and roosting in hollow trees, and 
even venturing into barns and out-buildings to sjDend the night. 
More eminently nocturnal than any of its kind, it does not emerge 
from its darksome quarters until the day has expired, and gloomy night 
has assumed the rod of emj^ire. In the uncertain twilight a few individ- 
uals, pressed by hunger, may often be seen abroad, but it is not until 
every trace of day has been obliterated that we find the majority on the 
wing, in noiseless jjursuit of game. When aroused during the daytime its 
movements are somewhat dubious, and it acts very much like a child who 
has been awakened from a sound sleep in the midst of a brilliantly-lighted 
room. In cloudy weather less difficulty is experienced, and its actions are 
freer. Young birds seem to be better adapted to sunlight than their 
parents. May it not be that the constant habit of slee|hng during the 
day, consequent upon a night’s carousal, has so weakened the visual organs 
as to render them ill-fitted for day-toil? Animals, accustomed to diurnal 
occupations, suffer considerable inconvenience for a while when comjDelled 
to w'ork at night. A return to day-labor is attended, though perhaps in 
a less degree, by the same discomfort. The irides undoubtedly habituate 
themselves to a reversal of habit. It is a notorious fact that the young 
of the Great-horned Owl can endure, the intense light of the sun almost 
equally with the Eagle, although being mainly nocturnal in habits. It is 
brought about by the voluntary, rather than the automatic, movements of 
the iris. This fact associated with the already mentioned circumstance in 
the history of the present species, strongly favors the hypothesis that all 
our Owls can in time adapt themselves to a change of habit passu 
with visual modification, as instanced in the case of the Day Owl. 
Appetitive gratification is the sole engrossing thought of these birds 
outside of the mating season. While they devote much of their time 
veering through the atmosphere in quest of insects which contribute largely 
to their diet, still they do not deem themselves too aerial to descend to 
the earth at times when some jjurpose is to be subserved. They are fond 
