XII 



(Fig. 267,^) is very 

 small, much shorter 

 than the tibia, and 

 tapers to a point at 

 its distal end. 



Following the 

 tibio-tarsus is an 

 elongated bone, the 

 tarso-metatarsus (ts. 

 mtts.\ presenting at 

 its proximal end a 

 concave surface for 

 the tibio-tarsus, and 

 at its distal end three 

 distinct pulleys for 

 the articulation of 

 the three forwardly- 

 directed toes. In the 

 young Bird the prox- 

 imal end of this bone 

 is a separate cartilage 

 (Fig. 268, tl.2\ re- 

 presenting the distal 

 tarsals, and followed 

 by three distinct 

 metatarsals, belong- 

 ing respectively to 

 the second, third, 

 and fourth digits. To 

 the inner or preaxial 

 side of the tarso- 

 metatarsus, near its 

 distal end, is attach- 

 ed by fibrous tissue 



PHYLUM CHORDATA 

 hi 



469 



ti.ls 





ph.* 



FIG. 267. Columba livia. Bones of the left hind- 

 limb, en. pr. cnemial process; fe. femur; fi. 

 fibula ; Jut. head of femur ; mtts.r, first metatar- 

 sal ; pat. patella ; ph.i, phalanx of first digit ; 

 ph. 4, phalanges of fourth digit ; //'. ts. tibio-tar- 

 sus '. ts. mtts. tarso-metatarsus ; tr. trochanter. 



