4S4f THfe PHILOSOPHt 



« ileep during winter, fuch as lizards, frogs, Sec. had a very 



< different conformation as to thofe organs : That all thofe 



< animals, he believes, do breathe in their torpid flate j and, 



< as far as his experience reaches, he knows they do ; and 



< that, therefore, he efteems it a very wild opinion, that ter- 

 ' reftrlal animals can remain any long time under water 

 ' without drowning.' Another argument againft their fub- 

 merfion rifes from the fpecific gravity of the animals them- 

 felves. Of all birds, the fvvallovv tribes are perhaps the 

 lighteft. Their plumage, and the comparative fmallnefs of 

 their weight, indicate that Nature deftined them to be almofl 

 perpetually on the wing in queft of food. From this fpeci- 

 fic lightnefs, the fubmerlion of fwallov/s, and their continu- 

 ing for months under water, amount to a phyfical impoffi- 

 bility. Even water-fowls, when they wifh to dive, are oblig- 

 ed to rife and plunge with confiderable exertion, in order to 

 overcome the reliftance of the water. Klein's idea of fwal- 

 lows employing reeds and ftraws as means of fubmerlion is 

 rather ludicrous j for thefe light fubftances, inftead of being 

 proper inftruments for affifting them to reach the bottom, 

 would infaUibly contribute to fupport them on the furface, 

 and prevent the very objeif}: of their intention. Befides, admit- 

 ting the poffibility of their reaching the bottom of lakes and 

 feas, and fuppofing they could exift for feveral months with- 

 out refpiratlon, what would be the confequence ^ The 

 whole would foon be devoured by otters, feals, and iiflies of 

 various kinds. Nature is always anxious for the prefervation 

 of fpecies. But, if the fwallovv tribes were deftined to re- 

 main torpid, during the winter months, at the bottom of 

 lakes and feas, Ihe would acSt in oppofition to her own inten- 

 tions ; for, in a feafon or two, the whole genus would be 

 annihilated* 



Mr. White of Selborne has favoured us with the follow- 

 ing information concerning the migration of fwallows : * If 



