BAT. 551 



possess them can, by their means, and with the 

 utmost efforts which their muscles are capable 

 of exerting, ever rise from the ground, or even 

 suspend themselves for a moment in the air. 



The only quadruped that can properly be said 

 to be endowed with the power of flying is the 

 Bat. In this animal the portions of the ske- 

 leton (f, Fig. 223) which correspond to the pha- 



langes of the fingers are extended to an enor- 

 mous length, and the pectoral muscles, which 

 move the anterior extremities, are of extraordi- 

 nary size and power. In the larger species, 

 each wing is at least two feet in length. The 

 fine membrane, which is spread between these 

 lengthened fingers, has its origin in the sides of 

 the neck, and reaches all along the body to the 

 extremities of the hinder legs, which it encloses 

 in its folds. Thus, not only is the surface, by 

 which it acts upon the air, sufiiciently extensive, 

 but the muscular power, by which its motions 

 are effected, is adequate to give it those quick 



