116 THE CAT. [CHAP. iv. 



fifth is very small and oval, and witli a long process or tuberosity 

 extending backwards on its outer side {x). 



The shafts of the four outer metatarsals arc flattened dorsally and 

 on their plantar surface, and where they are in contact towards their 

 proximal ends. That of the medius is the longest and the stoutest ; 

 that of the fifth digit is the most slender, and that of the index of 

 the foot, the shortest. Each of these four outer metatarsals develops 

 a rounded head at its distal end, which articulates with the concavity 

 on the hinder end of the proximal phalanx of the corresponding 

 digit. As in the corresponding part of the metacarpals, there is a 

 prominence developed at the middle of the ventral surface of each 

 such distal, articular head — a sesamoid bone playing in the concavity 

 which exists on each side of such prominence. 



§ 19. The PHALANGES are three in number in each digit, except 

 the first or hallux, which is devoid of any. 



In form and arrangement the phalanges of the hind-foot closely 

 resemble those of the fore-foot, except that the proximal ones of the 

 outermost (peroneal) digits are longer and stouter. 



^ 20. The ARTICULATIONS AND LIGAMENTS OF THE PELVIC GIRDLE 



are as follows : — 



In the first place, each ilium is united to the adjacent auricular 

 surface of the sacrum by cartilage which there coats both bones, and 

 forms what is called the sacro-iliac synchondrosis. Ligaments called 

 the dorsal and ventral sacro-iliac ligaments strengthen this articula- 

 tion on each side. The pubes are joined together at the symphysis by 

 the help of a fibro-cartilage, and by siqjerior and inferior lirjnments. 



The obturator foramen is closed by means of the obturator mem- 

 brane (or ligament), which is attached to its margin or inner edge. 



The socket ofiered by the bony pelvis to the head of the femur is 

 deep, but it is made still deeper by the cotyloid lirjament, which 

 surrounds its margin and bridges over the notch at its lower part, 

 forming there what is called the transverse ligament. 



The movements of the thigh, therefore, though still extensive, are 

 more restrained than those of the fore-limb at the shoulder-joint. 

 The head of the femur is held in its socket in part by a very strong 

 ligament called the Ugamcntum teres, which is at one extremity con- 

 tinuous with the transverse ligament, while at its other end it is 

 inserted into the pit on the head of the femur. 



The joint is surrounded by a capsular ligament, strongest in front, 

 attached above to the margin of the acetabulum and the transverse 

 ligament, and below to the intertrochanteric line in front, but at a 

 higher level behind. It is lined by synovial membrane. 



The ARTICULATIONS AND LIGAMENTS OF THE HIND-LEG are ex- 

 ceedingly complex. 



The internal lateral ligament (Fig. 74, i) extends from the internal 

 tuberosity of the femur to the inner tuberosity of the tibia. The 

 tendon of the semi- membranous muscle {sm) passes between it and 

 the bone. 



