XXII. 2 



SKELETON OF BATS 



587 



flight movements occur mostly at the shoulder, with the rest of the 

 limb held stiff. The radius is long and the ulna reduced and fused 

 with the radius; the elbow joint allows only flexion and extension. 

 The carpus is much specialized by fusion of bones, allowing flexion- 

 extension and spreading of the digits. Of the five fingers the first 

 is stout and free of the wing; it bears a claw in Microchiroptera, as 



Time. 10 minute intervals 



Fig. 366. Temperature chart of greater horseshoe bat. Manipulation during 

 attachment of thermocouple to back has caused warming at beginning of experiment. 

 Bat stimulated at points marked s. The black rectangles mark periods during which 

 the animal was shivering or moving. Room temperature 15-5° C. (From Burbank 



and Young.) 



does the second also in fruit bats. The remaining metacarpals and 

 proximal phalanges are enormously elongated to support the wing, the 

 distal phalanges being relatively short. As in birds the wings are short 

 and broad in the slower fliers (horseshoe bats), long and narrow in 

 those that fly faster, with long rapid beats (noctules). On landing 

 horseshoe bats turn a somersault forwards and catch on with the hind 

 legs. Others land on all fours and can walk reasonably well. 



The pelvis is rotated so that the acetabulum lies dorsally and the 

 limb is held outwards and upwards. The ventral portions of the girdle 

 are thus drawn apart and are often not united in a symphysis. The 

 hind legs are weak and carry five clawed digits, by which the animal 

 is suspended upside down when at rest, the tendons providing a catch 



