[ 276 ] 
turn, never with us congregating with tiieir cmgt;rt£ri 
in the autumn. Undoubtedly they breed a fecond time, 
like the houfe-martin and fwallow, and withdraw about 
hlichaelmas. Though in fome particular diftri61;s they 
may happen to abound, yet in the whole, in the South 
of England at leaft, is this much the rareft fpecies. For 
there are few towns or large villages but what abound 
with houfe-martins ; few churches, towers, or fteeples, 
but what are haunted by fome fwifts ; fcarce a hamlet or 
fingle cottage-chimney that has not its fwallow : while 
the bank-martins, fcattered here and there, Uve a fequef- 
tered life among fome abrupt fand-hills, and in the 
banks of fome few rivers. Thefe birds have a pecu- 
liar manner of flying; flitting about with odd jerks 
and vacillations, not unlike the motions of a butterfly. 
Doubtlefs the flight of all hirundines is influenced by, 
and adapted to, the peculiar fort of infects which fiunilh 
their food. Hence it would be worth enquiry to exa- 
mine, what particular genus of infecfls affords the prin- 
cipal food of each refpe<flive fpecies of fwallow. Sand- 
martins differ from their congeners in the diminutive- 
nefs of their fize and in their colour, which is what 
is ufually called a moufe-colour. Near Valentia m 
Spain they are taken and fold in the markets for the 
table; and are called by the country people, probably 
from their defultory, jerking manner of papilion 
de Montagna,.^ 
I am, with the greateft refpe6l, &c. 
XXIV. Account 
