LIFE OF WILSON. 
CXCl 
I have, at this time, in the press, a memoir on the migration 
and torpidity of these birds. lam confident that I shall he 
able to convince every candid philosopher., that great num- 
bers of swallows, of different species, do occasionally pass 
into a state of torpidity, more or less profound, not merely 
‘ in some remote quarter of America,’ but in the vicinity of 
our capital cities, where there are some men of genuine obser- 
vation and inquiry, and who are as little prepense to believe 
the marvellous in natural history, as any philosophers elsewhere. 
“ 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 ex- 
tensive inquiries have convinced me, that the instances of tor- 
pid swallows are much more frequent than I formerly supposed 
they were; and that there are two species of the genus Hirun- 
do, which are peculiarly disposed to pass the brumal season in 
the cavities of rocks, in the hollows of trees, and in other simi- 
lar situations, where they have often been found in a soporose 
state. These species are the Hirundo riparia, or sand swal- 
low; and the H. pelasgia, which we call chimney swallow. 
There is no fact in ornithology better established, than the 
FACT of the occasional torpidity of these two species of Hi- 
rundoP’*- 
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 ob- 
* Tilloch’s Philosopliical Magazine, vol. 35, p. 241. 
“ Natiu-alists,” says Dr. Bai-ton in another place, “ have not always been 
philosophers. The slxghl and superficial manner in which tliey have examined 
many of the subjects of tlieir science; the credulity which has accompanied 
them in their researches after trutli; and the precipitancy with which they have 
decided upon many questions of importance; are proofs of this assertion.” Me- 
moir concerning the fascinating faculty of serpents. 
