[ 297 ] 



Another reafo'n why the inftances of torpid fwal- 

 lows may not be expected fo frequently > is, that the 

 inftinct of fecreting themfelves at the proper feafon 

 of the year, likewife fuggefls to them, it's being 

 neceflary to hide themfelves in fuch holes and 

 caverns, as may not only elude the fearch of man, 

 but of every other animal which might prey upon 

 them ; it is not therefore by any common accident 

 that they are ever difcovered in a ftate of torpi- 

 dity. 



Since the ftudy of natural hiflory, however, hath 

 become more general, proofs of this fact are fre- 

 quently communicated, as may appear in the Britifh 

 Zoology *. 



That it may not be faid, however, I do not refer 

 to any inftance which deferves credit, if properly 

 fifted, I beg leave to cite the letter from Mr. Achard 

 to Mr. Collinfon, printed in the Philofophical Tranf- 

 actions "f-, from whence it feems to be a mo:ft irre~ 

 fragable facl, that fwallows $ are annually difcovered in 

 a torpid ftate on the banks of the Rhine. I mail alfo 

 refer to Dr. Birch's Hiftory of the Royal Society |J, 

 where it is flated, that the celebrated Harvey dhTe&ed 



* See Vol. II. p. 250. Brit. Zoo3. ill. p. 13, 14. As alfo 

 Mr. Pennant's Tour in Scotland, p. 199. 



f 1763, p. 101. 



I " Swallows or martins," are Mr. Achard's words, which 

 I the rather mention, becaufe Mr. Collinfon complains that the 

 fpecies is not fpecified. 



Mr. Collinfon himfelf had endeavoured to prove, that fand 

 martins are not torpid, Phil. Tranf. 1760, p. 109. and con- 

 cludes his letter, by fuppofing that all the fwallow tribe migrates,, 

 therefore the fwift is the only fpecies remaining ; for his friend 

 Mr. Achard ftiews to demonftration, that fwallows or martins 

 are torpid ; he does not, indeed, precifely ftate which of them. 



IS Vol. IV. p. 537. 



Vol. L XII. Q^q fome, 



