LOCOMOTION. 229 



Anatomy of the Leg of a Bird at rest : after Borelli. ct, a muscle which 

 arises from the haunch-bone, and, becoming suddenly tendinous, passes 

 the outer angle of the thigh-joint at b ; then, winding round the leg-bone, 

 it slips over the outer angle of the leg-joint at c, proceeds forwards to 

 the palm of the foot, divides, and is inserted into the bones of the toes. 



become strongly clasped. 



in its sleep is easily procured, and children, who 

 in general are fond of the experiment, can demonstrate 

 the fact that Borelli has explained, and which he has 

 explained by descriptions of the muscles sufficiently 

 minute and sufficiently accurate to support his con- 

 clusions*.'' 



It is owing to the same ingenious mechanism that 

 birds can rest on one leg as easily, perhaps more so, 

 than upon both ; at least the fact is certain, however it 

 may be accounted for by Vicq d'Azyr and Barthez, 

 that a great proportion of birds sleep standing on one 



* On Muscular Motion, p. 439. 



z3 



