158 



ANIMAL SKETCHES. 



CHAP. 



increased to a couple of score in the albatross. These long, 

 narrow wings are characteristic of birds of a strong-sus- 

 tained flight. It has been shown that when a bird is cleaving 

 rapidly through the air a narrow pinion is as effectual as, 

 or even more effectual than, a wing with more ample 

 surface. But the possessors of such narrow wing-blades 

 find it difficult to start. The swallows and swifts generally 

 plunge from a height which enables them to drop through 



the air, and thus at once acquire a sufficient velocity. But 

 the frigate-bird, which has perhaps the longest wings for 

 the bulk of its body of all birds, has great difficulty in 

 rising from the surface of the sea. A short, broad wing is 

 better for a rapid start. The frightened pheasant or 

 partridge whirrs off at a moment's notice ; but it cannot 

 sustain a long flight. 



