192 



The Bird 



bend the tarsus back and forth in the leg of a dead chicken, 

 the workings of these strands of tissue may be traced 

 beneath the scales. Reference to the photograph, where 

 catgut replaces these tendons, will make their workings 

 still more plain. 



Fig. 141.— Same as Fig. 140; toes contracted. 



Many birds cannot flex the leg without drawing the 

 toes up, and we may be sure that these birds are safe 

 when they perch; the closer the}^ sit to the branch the 

 tighter becomes their grip. But this safety mechanism 

 is not found in all perching birds by any means (Fig. 

 143). 



A strange thing about muscles is that there are fine 



