OF LA PEROUSE, 1 17 



The manner of flying of thefe birds is very 

 aftonifhing. The flapping of their wings is not 

 perceptible till the moment when they take their . 

 flight ; and very often they, at the fame time, 

 employ their feet, which, being palmated, ferve 

 them to ftrike the water repeatedly, in order to 

 raife themfelves : this impulfe once given, they 

 have no longer any occaiion to flap their wings; 

 they keep them very much fpread, and feek their 

 prey balancing themfelves alternately from right 

 to left, and Ikimming rapidly along the furface 

 of the fca. The equilibrium thus obtained, 

 ferves, no doubt, to accelerate their progrefs ; 

 but it does not feem likely to be fufficient for 

 fupporting them in the air. Perhaps an imper- 

 ceptible tremor of their feathers is the principal 

 caufe of this extraordinary flight : on this fup- 

 pofition, they muft neceflarily have particular 

 mufcles ; for which reafon I think that the ana- 

 tomy of thefe birds merits the greateft attention. 



The fuffins of Buffon (procellaria puffinus, 

 Linn ) were very numerous in thefe feas. The 

 flight of this bird is executed by a mechanifm 

 analogous to that of the albatrofs, for it fre- 

 quently flies a long time without any perceptible 

 flapping of the wings ; it is only when it in- 

 clines from one fide to the other that it is fecn 

 to ftrikc the air with its loweft wing, in order to 

 -turn about inflantly. 



1 s The 



