cell 
LIFE OF WILSON. 
«I do not suppose that all the Swallows of North America 
become torpid. It is my present opinion, and it was my opinion 
when I published the “ Fragments” in 1799, that the Swallows, in 
general, are migratory birds. But subsequent and very extensive 
inquiries have convinced me, that the instances of torpid Swallows 
are much more frequent than I formerly supposed they were ; and 
that there are two species of the genus Hirundo^ which are peculi- 
arly disposed to pass the brumal season in the cavities of rocks, in 
the hollows of trees, and in other similar situations, where they 
have often been found in a soporose state. These species are the 
Hirundo riparia, or Sand Swallow ; and the H, pelasgia, which we 
call Chimney Swallow. There is no fact in ornithology better esta- 
blished, than THE FACT of the occasional torpidity of these two species 
of Hirundo 
It is not strange that the very extensive^^ inquiries of our 
learned professor should have had a result so different from those 
of Wilson, an ornithologist infinitely better qualified than himself 
to investigate a question of this kind, by his zeal, his capacity, and 
his experience. Who those men of genuine observation and inquiry 
were, who resided in the vicinity of our capital cities, he did not 
condescend to inform us ; if he had done so, Ave should be enabled 
to determine whether or not they were capacitated to give an opi- 
nion on a subject which requires qualifications of a peculiar kind. 
At the time in which the professor wrote the above cited let- 
ter, I know of but two naturalists in the United States Avhose opin- 
ions ought to have any weight on the question before us, and these 
were William Bartram and Alexander Wilson, both of Avhom have 
* Tilloch’s Philosophical Magazine, vol. 35, p. 241. 
“ Naturalists,” says Dr. Barton in another place, “ have not always been philosophers. The 
slight and superficial manner in which they have examined many of the subjects of their science ; 
the credulity which has accompanied them in their researches after truth ; and the precipitancy 
with which they have decided upon many questions of importance ; are proofs of this assertion.” 
Memoir concerning the Fascinating Faculty of Serpents, 
