48 
INTRODUCTION. 
their summer abodes, the desolate regions of Greenland and 
Spitzbergen, to the fens and sea-shores of the West India islands 
and South America, the usual places of their winter retreat, 
while those of the Purple Martin and common Swallow still 
remain, in vulgar belief wrapt up in all the darkness of mys- 
tery. 
Philadelphia^ March \sty 1819. 
