vI 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 
Fic. 44. 
Flexor tendons of toes in (a) Fowl; (4)—after Gadow—Passerine Bird. (1) deep, 
divided tendon ; (2) the tendon that bends the hallux or firsttoe. In Passerine Birds 
they remain unconnected. 
connection have been found very useful in classifica- 
tion! 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. 
