STORM PETRELS. 419 



the breast. The toes are of the same length as in the sooty 

 petrel, and the tarsi also nearly the same ; but the bill is 

 rather shorter and stouter, approaching more to the character 

 of that of the fulmar, only without the elevated and distinct 

 nasal tube. 



STORM PETRELS (TJialassidromo). 



The name tlialassidroma, " coursers over the sea," imitators, 

 as it were, of the far journeys and fleet motion of the camel 

 over the desert, is very expressive of the habits of these sin- 

 gular birds, birds which, unless during the breeding time, 

 appear to make the sea more exclusively their dwelling-place, 

 than perhaps any other of the feathered tribes. They skim 

 the surface, and while the wings are expanded and acting in 

 the air, the feet, which are then bent like little scoops, " tip" 

 the water like paddles, and add the motion of walking to 

 that of flying. The feathers of the breast generally also 

 brush the surface during those excursions, which are skimming 

 ones in more senses than one, as the birds not only skim 

 along the surface, but skim the floating oil which that sur- 

 face bears in very copious quantity, but on the wide sea and 

 away from the remains of those oily animals from which it 

 in great part proceeds, so thin and filmy that no bird could 

 feed upon it by means of the bill. The feathers on the breast 

 of the storm-petrel are, like those of all swimming birds, 

 waterproof ; but substances not susceptible of being wetted 

 with water, are, for that very reason, the best fitted for col- 

 lecting oil from its surface. That function is performed by 

 the feathers on the breasts of the storm petrels, as they brush 

 over the surface ; and though that may not be the only way in 

 which they procure their food, it is certainly that in which 

 they obtain great part of it. They dash along till th.;y have 



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