AVES—SWIFT. 571 
wings, and tail being black, glossed with purple; and the under parts white. 
They are much less agile than the chimney swallow, and have a placid, easy 
motion. These birds sometimes build against the sides of cliffs that over- 
hang the sea; but more frequently under the eaves, in the corners of win- 
dows, or under cornices. The materials of the nest are earth, tempered and 
mixed with straw, and lined with small straws, grasses, and feathers. The 
little architect builds only during the morning, and allows the fabric to 
harden during the rest of the day. The same nest is often inhabited for 
several years. 
THES WET e+ 
‘l'nts is the largest of the swallow kind known in England, being often 
eighteen inches long, though the entire weight of the bird is not more than 
one ounce. The whole plumage is of a sooty black, except the throat, which 
is white. The feet, which are so small that the actions of walking and 
rising from the ground seem very difficult, are of a particular structure, all 
the toes standing forward. For this reason, the swift never settles on the 
ground, unless by accident. They have, however, a strong grasp with their 
feet, which enables them to cling to walls. It spends more of its time on 
the wing than any other swallow, and its flight is more rapid. In summer 
it keeps on the wing at least sixteen hours out of the twenty-four. It 
breeds under the eaves of houses, in steeples, and other lofty buildings; and 
makes its nest of grass and feathers. It has but one brood in the summer, 
and never more than two young ones at a time. 
The voice of the swift is a harsh scream; yet there are few ears to which 
it is not pleasing, from an agreeable association of ideas, since it is never 
heard but in the most lovely summer weather. 
These birds visit England the latest, and retire the earliest, of all their 
tribes; as they withdraw from that country before the middle of August, 
generally by the tenth, and nota single straggler is to be seen by the 
twentieth. This early retreat is totally unaccountable, as that time is often 
the most delightful in the year. But, what is yet more extraordinary, they 
begin to retire still earlier in the most southerly parts of Andalusia; where 
they can by no means be influenced by any defect of heat, or even of food. 

1 Cypselus murarius, Temm. The genus Cypselus has the bill very short, triangular. 
broad at the base, inconspicuous, depressed ; gape as far as under the eyes; npper mandi- 
ble hooked at the tip; nostrils cleft longitudinally, at the upper part of the Ill, open, and 
the raised margins furnished with small feathers; legs very short, with the fore toes 
directed forwards, and quit: divided ; three toes, and claws short and thick; wings very 
long, tail with ten feathers. 
