154 
NATURAL HISTORY OF SELBORNE. 
After so much labour is bestowed in erecting a mansion, as 
nature seldom works in vain, martins will breed on for several 
years together in the same nest, where it happens to be well 
sheltered and secure from the injuries of weather. The shell or 
crust of the nest is a sort of rustic-work full of knobs and pro- 
tuberances on the outside : nor is the inside of those that I have 
examined smoothed with any exactness at all ; but is rendered 
soft and warm, and fit for incubation, by a hning of smaU straws, 
grasses, and feathers ; and sometimes by a bed of moss interwoven 
with wool. In this nest they tread, or engender, frequently 
during the time of building; and the hen lays from 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 
aflfectionate 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 nest- 
lings 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 them- 
selves 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 rjXiKLa, or full growth, they soon become impatient of con- 
finement, 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 al- - 
most imperceptible a slight, 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 oflf and rejected by their 
able authority, of eave swallows (or *' martins") congregating to the assistance of the injured 
pair, and immuring the sitting sparrow in its usurped abode. Generally speaking, however, the 
sparrow contrives to maintain possession comparatively unmolested. — Ed. 
* This envelope appears to be somehow occasioned by the still quiet life which is led bj-^ nest- 
lings. An adult haw-grosbeak, which I kept for some time in conflnement, having broken his 
leg, which prevented him from getting about, his mutings were in consequence encased like 
those of a young bird. — Ed. 
