WINDOW SWALLOW. 
551 
pear, 1 have no hesitation in pronouncing it to be altogether fabu- 
lous. Swallows, I admit, may be frequently seen both drinking 
and washing on the wing, and also collecting mud from cart-ruts 
and other places ; but never carrying water in their bills, or on 
their feathers, neither of which are they capable of performing ; for 
they want the necessary muscles to carry water in their mouths as we 
can do, and whatever water might adhere to their feathers, would be 
instantly shaken off in flying, let the dust, which requires sprinkling, 
be as near as it might, for, according to my observation, it runs off 
from them as it does from the feathers of ducks and other water fowl. 
Besides their not being able to find materials sufficiently moist, is a 
supposition altogether gratuitous and improbable, with respect to a bird 
of such powerful wing, whose flight is so excursive, and usually in the 
vicinity of water. 
That some liquid is requisite, however, to make their mortar more 
adhesive, will be evident to any person who will take the trouble of 
picking up a little mud from the same place where the swallows collect 
it, and trying to make it adhere to a wall as they do in their nests. I 
have more than once tried such an experiment without success, and 
have thence been led to conclude that the swallows employ some sali- 
vary fluid besides the water which may be in the mud. That this is 
the fact, and not a fancy, may be easily proved, as it is, in numerous 
instances ; and it is not adverting to this, that the building of nests 
has been so ill understood by naturalists, and so many fanciful accounts 
of the matter have been promulgated. I have further ascertained, by 
examining nests during the process of building, that the portion of 
clay just added, is considerably more moist than that of the ruts from 
which it has been taken, a stronger proof that the bird moistens it 
with saliva, than is afforded by merely finding larger salivary glands, 
which is proved by dissection to be the case. ^ 
Pennant says he has seen them build in cliffs overhanging the sea. 
I am acquainted with one locality where they build in a similar man- 
ner, at the beautifully romantic dell of Hawford, near Catrine, in 
Ayrshire, where the river Ayr winds among wooded rocks, from one 
to three hundred feet above its channel. There the nests are few in 
number, and not crowded together, but scattered singly among the 
cliffs. In this country, at least, the species is only subgregarious, par- 
ties of some three, four, or half a dozen, selecting the same window or 
several windows on the same frontage. The greatest number I ever 
' Architecture of Birds. Chap, on Mason Birds, p. 101. 
