THE HIND-LIMB. 423 



facets for the tibio-tarsua ; on its posterior surface 

 is a prominent ridge, deeply grooved behind, and 

 traversed at its base by a longitudinal canal, for 

 the passage of the tendons of the flexor muscles of 

 the toes. Behind the ridge, two sesamoid bones 

 are usually present. 



In the shaft of the bone, three metatarsals 

 can easily be distinguished. They do not lie 

 quite parallel to one another, the middle one 

 being slightly posterior to the other two at its 

 proximal end, and anterior distally. 



At the distal end of the bone, the three meta- 

 tarsals separate from one another, and each ends 

 in a pulley-like surface for the corresponding 

 digit. 

 b. The first metatarsal is incomplete, its distal end 

 alone being ossified. It is a small irregular 

 nodule of bone, attached by ligament to the inner 

 and posterior surface of the tarso-metatarsus, a 

 short distance above its distal end. 

 0. The digits. The four preaxial digits are present. 

 In many domestic fowls, notably Dorkings, an 

 extra or supernumerary toe is present on the 

 inner side of the foot. The true fifth, or postaxial 

 digit, is always absent, 

 i. The hallux, or great toe, is connected with the 

 first metatarsal, and directed backwards. I 

 consists of two phalanges, the last one bearing 

 a claw, 

 ii. The second toe is directed forwards and slightly 

 inwards. It has three phalanges, the last one 

 clawed, 

 iii. The third toe is the largest and is directed for- 

 wards. It has four phalanges, the terminal 

 one clawed, 

 iv. The fourth toe is directed forwards and out- 

 wards. It has five phalanges, and the distal 

 one is clawed. 



