64 



Animal Life and Intelligence. 



palm of our hand. They are the metacarpals, and are 

 numbered n., in., iv., and v. in the tabulated figures in which 

 the observations are recorded. The metacarpals of the 

 second and third digits run tolerably close together, and 

 form the firm support of the anterior margin of the wing. 



Fig. 12. "Wing" of bat (Pipistrelle). 



Hu., humerus, or arm-bone; Ul., conjoined radius and ulna, a bone in the forearm; Po., 

 pollex, answering to our thumb; n., in., iv., v., second, third, fourth, and fifth digits of the 

 manus, or hand. The figures are placed near the metacarpals, or palm-bones. These are 

 followed by the phalanges. Fe., femur or thigh-bone; 2V., tibia, the chief bone of the shank. 

 The digits of the pes, or foot, are short and bear claws. Ca., calcar. 



Those of the third and fourth make a considerable angle 

 with these and with each other, and form the stays of the 

 mid part of the wing. Beyond the metacarpals are the 

 smaller joints or phalanges of the digits, two or three to 

 each digit. The third digit forms the anterior point or 

 apex of the wing. The fourth and fifth digits form 

 secondary points behind this. Between these points the 

 wing is scalloped into bays. 



From the point of the fifth or last digit the leathery 

 wing membrane sweeps back to the ankle. The bones of 

 the hind limb are the femur, or thigh-bone, and the tibia 

 (with a slender, imperfectly developed fibula). There are 

 five toes, which bear long claws. From the ankle there 

 runs backward a long, bony and gristly spur, which serves 



