36 ANIMAL LIFE PAST AND PRESENT. 



third, fourth, and fifth, which have no claws at the 

 end, are absolutely longer than either the fore-arm or 

 the arm. Between these elongated spider- like fingers 

 the wing-membrane is stretched, the whole structure 

 permitting of the wing being folded, when at rest, in 



FlQ. 13. The bones of the right fore-limb of a Bat, seen from above. 

 h. bone of arm; r.u. bones of fore-arm; px. thumb; ph. claw of 

 thumb ; m.c. metacarpus ; pW, 2nd, 3rd, 4th, and 5th fingers. 



the manner familiar to all. A comparison of Fig. 13 

 with Fig. 11, or, still better, with the figure of the 

 skeleton of a Pterodactyle, given in the chapter on 

 Flying Dragons, will show how essentially the wing of 

 a Bat differs from that of a Pterodactyle. As we 

 have said, the single finger supporting the wing- 



