SWALLOW TRIBE. 87 
tins, after taking possession of a nest which had been 
constructed in the preceding summer, drew out the 
dried bodies of three nearly full-fledged nestlings 
which had perished in it, preparatory to appropriating 
it to their own purposes. About the same time, and 
near the same spot, a similar attempt was made by 
another pair of House-Martins; but all their efforts 
to dislodge the young proving ineffectual, they en- 
tirely closed up the aperture with clay, and so con- 
verted the nest into a sepulchre. 
At first I was disposed to attribute the untimely 
fate of the nestlings thus unexpectedly discovered to 
the accidental destruction of one or both of their 
_ parents; but a little reflection induced me to change 
my opinion. So many instances were called to mind 
of the sudden departure of House-Martins, at periods 
when, to all appearance, they were most busily en- 
gaged in providing for their families, that what before 
was regarded as the unavoidable consequence of a 
fortuitous circumstance, I now began to suspect might 
be occasioned by a voluntary act of desertion. 
In order to clear up this doubtful point, an exa- 
mination of a considerable number of Swallows’ and 
House-Martins’ nests was immediately resolved 
upon; but, as the breeding-season had then com- 
menced, it was deemed advisable, on more mature 
deliberation, to defer the undertaking until its ter- 
mination: accordingly the search was postponed to 
the 27th of October, when, on being carried into 
