three to five white eggs.

At first when the young are hatched, and are in a naked and helpless
condition, the parent birds, with tender assiduity, carry out what comes
away from their young. Was it not for this affectionate cleanliness the
nestlings would soon be burnt up, and destroyed in so deep and hollow a
nest, by their own caustic excrement. In the quadruped creation the same
neat precaution is made use of, particularly among dogs and cats, where
the dams lick away what proceeds from their young. But in birds there
seems to be a particular provision, that the dung of nestlings is
enveloped in a tough kind of jelly, and therefore is the easier conveyed
off without soiling or daubing. Yet, as nature is cleanly in all her
ways, the young perform this office for themselves in a little time by
thrusting their tails out at the aperture of their nest. As the young of
small birds presently arrive at their [Greek text], or full growth, they
soon become impatient of confinement, and sit all day with their heads
out at the orifice, where the dams, by clinging to the nest, supply them
with food from morning to night. For a time the young are fed on the
wing by their parents; but the feat is done by so quick and almost
imperceptible a flight that a person must have attended very exactly to
their motions before he would be able to perceive it. As soon as the
young are able to shift for themselves, the dams immediately turn their
thoughts to the business of a second brood; while the first flight,
shaken off and rejected by their nurses, congregate in great flocks, and
are the birds that are seen clustering and hovering on sunny mornings and
evenings round towers and steeples, and on the roofs of churches and
houses. These congregatings usually begin to take place about the first
week in August, and therefore we may conclude that by that time the first
flight is pretty well over. The young of this species do not quit their
abodes altogether; but the more forward birds get abroad some days before
the rest. These approaching the eaves of buildings, and playing about
before them, make people think that several old ones attend one nest.
They are often capricious in fixing on a nesting-place, beginning many
edifices, and leaving them unfinished; but when once a nest is completed
in a sheltered place, it serves for several seasons. Those which breed
in a ready finished house get the start in hatching of those that build
new