640 CLASS AVES. 



very rapidly with their feet, which has caused them to be 

 compared to *S'^. Peter walking upon the water. 



The petrels are to be seen in all seas of the globe from one 

 pole to the other. They are the inseparable companions of 

 mariners, during their long navigations. Those which are 

 most frequently met, are the Procellaria Capensis, and the 

 smallest species. The flight of these birds is almost always 

 performed by hovering, and without presenting apparent 

 vibrations. They rise with facility, and can fly against the 

 strongest winds, which never slacken their movements. The 

 tempest not only does not affright them, but they are almost 

 necessitated to seek those seas where the agitation of the 

 waves bring to the surface those marine animals which con- 

 stitute their food. In consequence of this, they are frequently 

 seen in all weathers, in the vortices which are formed by 

 the track of vessels. 



These birds drop upon their prey with extreme prompti- 

 tude, and carry it off with their bill, as with a harpoon ; but 

 they have not the habit of diving, to attain it. They are, in 

 fact, never seen to submerge, and when the animal they are 

 watching is somewhat below the surface, they sink a portion 

 of their body in the water to seize it. 



That fish constitute the principal aliment of the petrels, 

 seems to be an error. Neither their habits, nor the structure 

 of their bill, appear adapted for fishing. It seems more 

 natural to regard dead cetacea as their preferable food, and 

 moUusca, marine worms, and the spawn of fish, as furnishing, 

 particularly to the smaller species, an habitual nutriment. 



The petrels, finding the sea to be always a suitable element 

 to them, do not quit it, except at the time of laying, and for 

 the purpose of making their nests upon very precipitous rocks, 

 where the}^ feed their young on half digested animals. They 

 retire there during the night, and utter a most disagreeable 



