MUSCULAR SYSTEM OF MAMMALIA. 51 



front of the biceps, to be inserted into the tuberosity of the 

 radius : it answers to 8, fig. 18, in Ungulates. The biceps, in 

 Felines, derives its single head from the upper rim of the glenoid 

 cavity, and is inserted into the bicipital tuberosity of the radius. 

 The ' brachialis internus ' is a long muscle on the outer side of 

 the humerus, and is inserted into the lower wall of the sigmoid 

 cavity of the ulna. The ( triceps extensor' is represented by 

 three or more muscles, distinct in their fleshy part, and remark- 

 able for their volume in Felines : their common tendon incloses 

 the olecranon like a strong capsule. Besides the foregoing there 

 are three shorter extensors, one of which is represented by the 

 human c anconeus ; ' but all belong to the same system as the 

 tricipital extensor. The ' pronator teres ' is proportionally large : 

 in the Lion its carneous part extends far down the fore-arm : in 

 the Cat it ends in the tendon inserted about half way down the 

 radius. The ' palmaris longus ' is also more developed than in 

 man. The ' supinator longus,' on the other hand, has a short 

 and slender fleshy portion ; and this relates to the habitual prone 

 position of the paw in Carnivora. The flexors and extensors of 

 the carpus and manus closely accord with those of Man, but with 

 excess of fleshy fibres in the larger Felines ; and a minor degree of 

 distinction of some muscles, as, e. g. s the * flexores digitorum,' and 

 I extensores pollicis.' The ' extensor longus pollicis ' has its origin 

 from the outer wall of the sigmoid cavity of the ulna and the 

 upper third of that bone : its long and slender tendon is inserted 

 into the first phalanx of the pollex, but usually, also, into that of 

 the index. By this insertion, as well as by its high origin, it is 

 less differentiated from the ' common extensor digitorum ' than in 

 Man. There is no * extensor brevis pollicis.' The ' indicator ' 

 is represented, in Felines, by a short and slender muscle from the 

 lower half of the outer side of the ulna : its tendon glides through 

 the same carpal synovial sheath as that of the extensor longus 

 pollicis : it has not a separate insertion into the index, but blends 

 with the tendinous division of the common extensor going to that 

 digit. The differentiation establishing the muscle as a true or 

 independent ( indicator ' has not yet come about. 



The ( flexor sublimis ' is a powerful muscle and the principal 

 bender of the paw in ordinary locomotion ; its origin is restricted 

 to the humerus ; its insertions are extended into all the five digits 

 by the fascias attached to the sides of the metacarpo-phalangial 

 joints, as well as the ordinary perforated tendons into the sides of 

 the first and second phalanges. The ( flexor, profundus ' arises by 

 five heads from the antibrachium, which form a common flattened 



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