\ I 



FORM AND FUNCTION 



167 



branching tendon is the one to which most interest 

 attaches, and it is easily distinguished from the others : 

 it lies the most deeply imbedded of all at the ankle- 

 joint, in a cartilaginous or bony tunnel. In a great 

 many birds it connects with the tendon that bends the 

 Hallux, and the absence of connection or the form of 



Fig. 44. 



Flexor tendons of toes 'm(a) Fowl; (l>)— after Gadow — Passerine Bird. (1) deep, 

 divided tendon ; (2) the tendon that bends the hallux or first toe. In Passerine Birds 

 they remain unconnected. 



connection have been found very useful in classifica- 

 tion. 1 Tracing the tendons upwards we shall find 

 them passing into muscles that arise partly from the 



1 Some of the chief varieties are well shown in specimens at 

 the British Museum, S. Kensington, but it is much the best 

 plan to dissect them out. 



