birds. 
*93 
vanccd to fupport the fatigue of a migration; or at moft, that 
thefe fafls may apply only to fome fpecies. Norfhouldit be 
omitted, that in 1757, by the direftion of Mr. Collinfon, a 
bank of a river, perforated with the holes of the Sand Mar¬ 
tin, was accurately fearched, in order to find fome of thefe 
birds, but without fucccfs. It is farther objefted, that if this 
opinion, of their torpor arifing from cold, was well founded, 
when the feafons are mild, in autumn, they ought not to dif- 
appearfo foon; and when we have warm weather in Febru¬ 
ary or March, they flrould appear foOner; this, it is faid, is 
not the cafe. 
Th e third notion, that they remain concealed under water, 
or in the mud, during the winter, is ftill more extraordinary ; 
and from its being contrary to all analogy, feems to re¬ 
quire the flrongeft fupport from aflual obfervation. 
^ It was firft fuggefted by Olaus Magnus, Archbifhop of 
Upfal, who fays, that they are often found in cluttered 
mattes at the bottom of the northern lakes, beak to beak 
wing to wing, and foot to foot. That when they are taken 
by experienced filhermen, they throw them 'in again ; 
but thofe who are unexperienced, by expofing them to 
warmth, revive them, it is true, but that this premature 
refurreftion is attended only by a ttiort renewal of their 
powers. 
Some very refpeaable Natural Hittorians have favoured 
this opinion ; amongft others, the father, and founder of this 
fcience, the great Linnaeus. Klein has adopted the lame 
opinion, and even produced certificates; they are princi¬ 
pally figned by one perfon, and (peak of a folitary inflancc, 
which happened long before, in the years of childhood, or 
elfe are founded upon hearfay, and admitted to be uncom¬ 
mon. 
PART VI. 
I 
Etmulles 
