members of the species never rest save in their headquarters, clinging to
the roof or the nests and never utter a sound except the reassuring,
prattle upon alighting on the edge of the nest. It was interesting to
note that while many young birds were fluttering about in the cave none
occupied a nest, and eggs were in successive stages of incubation, as
proved by appearance and test.

The fact that the nests of these swifts are cemented with coagulated
saliva establishes analogy with that other member of the family which
builds in the caves of frowning precipices near the sea, making edible
nests greatly appreciated by Chinese gourmands, some of whom maintain the
fantastic theory that the swift catches quantities of a small, delicately
flavoured fish which it exposes on rocks until desiccated, to be
afterwards compounded into nests. The ancients were wont to believe in
the existence of hostile mutuality between the swifts and the
beche-de-mer, though they have little in common in respect of appearance,
attributes, and habits. If memory serves, one of the genera had the
specific title of HIRUNDO, founded on the faith that the swift, by flying
over the sea-slug exposed by receding tide, and vexing it by jeers,
caused it to exude glutinous threads which the swift seized and bore away
to its cave to be consolidated and moulded into a nest. To the fable was
appended a retributive moral, viz., that the beche-de-mer occasionally
revenged itself by expelling such a complicated mass of gluten that it
became a net for the capture of the swift, which was slowly assimilated
by its enemy. The Chinese, it may be said, with but slight perversion of
fact, show equal partiality for the respective emblems of speed and
sloth.

Since the dates mentioned it has been ascertained by personal observation
that the breeding season of the swiftlet extends over four months,