^4 - ANIMALCULA OF INFUSIONS. I. 



lethai-gic in winter ; fo much the more, as he 

 learns from M. Adanfon, that common fwallows 

 conftantly appear in Senegal during autumn, and 

 dilappear in fpring : and he conceives the Euro- 

 pean fwallows, and thofe fubjed to lethargy, of 

 different fpecies, though they have hitherto been 

 clleemed the fame. 



Neither are fome wanting in the immenfe tribe 

 of fifhes on which cold produces a fmiilar effeft. 

 Tench, if we may credit Pechlin, as quoted by Mai- 

 ler, are of this defcription ( i ). In the beginning 

 of winter, he has obferved them bury themfelves 

 in the mud, juft as we have feen many reptiles 

 and infefts do in the earth. Speaking in gene- 

 ral terms, fifiies are a clafs of animals enjoying 

 the privilege of preferving adion and vivacity, 

 however cold the atmofphere may be, not only 

 becaufe fluid water can never acquire a great 

 portion of cold, but becaufe they may retire ftill 

 deeper and deeper whatever is the cold it ac- 

 quires (2). ^ 



Whence 



( 1 ) Ad Praeledion. Boerhaav. T. 4. Holier, PhyfioL 

 T. 5. 



(2) The poffibility of fifhcs becoming torpid has been 



doubted. A few experiments which I hare made on fe* 

 veral fmall fifties feemed to indicate torpor. When ex- 

 pofed to confiderable cold, though lefs than freezing, they 

 funk motionlcfs to the bottom of a vefl*cl, and immediate- 



It- 



