206 



CLASS AVES. 



rupted surface to the air, and the wing itself, actuated by forces 

 of less energy, fails of producing so perfect an effect. We find, 

 therefore, that these birds can only fly with advantage when the 

 wind is in their rear. They keep their heads low, and seldom 

 rise but for the purpose of discovering their prey. The French 

 term planer (to hover) very appropriately depicts this mode of 

 flying, in which the wings are extended and motionless, and 

 the body is carried along by the course of the wind. In fact, 

 it is, strictly speaking, a sort of sailing. The quills of the 

 rowing wing are also, in general, more firm than those of the 

 saiUng. This is indicated, according to M. Huber, by the lively 

 and marked variegat'on which predominates i*i the first from 

 one end to the other ; while, in the last, a deep, uniform black 

 wash pre\ails from the sloping of the feather to the point, and 

 a white equally uniform from the origin of the quill to the com- 

 mencement of the sloping. 



There is, likewise, a different conformation in the talons of 

 the rowers and sailers. These talons the falconers call hands 

 (mains). The toes in the former birds, or in the noble division 

 of birds of prey, are longer, finer, and more supple. They 

 embrace a more ex( ended surface, and being moved by a 

 longer lever, they are capable of a more powerful retention 

 than those of the sailing or ignoble birds, which are thicker and 

 shorter. The claws of the rowers, also, being more curved and 

 acerated, penetrate more easily, and inflict a more dangerous 

 wound. 



The rapacious birds employ the weapons with which nature 

 has provided them with the most admirable dexterity. The 

 rowing birds seize at once their intended victims, when the latter 

 are more light of body than rapid in their movements. When 

 the prey is of greater weight, and more activity, they strike it to 

 weaken and diminish its strength and speed. With an instinc- 

 tive precision the most extraordinary, they instantly attack the 

 vital part, which in the birds is at the hollow of the occiput, 

 and between the shoulder and the ribs in the mammalia. It is 



