MUSCLES OF THE ANTERIOR LIMBS. 



333 



The lateral extensor of the phalanges of Ruminants is tliicker than in the Horse, and con- 

 etitutes tlio proper extensor of the external digit (Fig. 185, 5). Its terniiiiul tendon (4', 6, 7) 

 comports itself exactly the same as thut of tlie proper extensor of the iuturnal digit, and, con- 

 sequintly, does not merit special description. We may remark, 

 ■with Lecoq, that these two muscles separate the digits from 

 each oth' r in extending them; they are, therefore, to a certain 

 poiut, antagonists of the common extensor. 



The obliijue flexor of the metacarpus in tlie Camel has a 

 very thin ulnar portion, rather aponeurotic tliaii muscular. 

 Tlie inferior tendon of that mu.scle, at its insertion into the pisi- 

 form boi.e, detaches a baud to the internal border of the carpus. 

 In this animal, tiie internal flexor is attached to the superior 

 extreiiiity of tlie internal border of the metaeaipu.-i. 



The perforatiis of the Ox and Sheep is composed of two por- 

 tions, the tendons of which unite towaid-s the middle of tlie 

 metacarpal region. The siugle tendon (Fig. 186,1,2, 3) which 

 results from this union afterwards divides into two branches, 

 each of wliicli comports itself, in reg.ird to the digits, as the 

 single perforatus tendon does in the Horse, except that they 

 receive from the suspensory ligament a fibrous band analogous 

 to that which, in Solipeds. goes to the perforans tendon. This 

 band (Fig. 185, I'A) concurs in the formation of the annular 

 ligament tlirough which the latter tendon passes. 



In the Camd, the muscular portion of the per.oratus is not 

 present, but is represented by a tendinous band, the arrangement 

 of which is curious. It arises from the common po8t(;rior liga- 

 ment of the carpus, and at its origin adheres firmly to the branch 

 of the susjjensory ligament of the fetlock which descends from the 

 pisiform bone ; it goes behind the perforans tendon, where it is 

 completely covered by a very strong white membrane, and about 

 the middle of the metacarpus it divides into two branches which 

 separate at a very acute angle. Each of these branches glides in 

 the sesamoideaii sheath, the posterior wall of which is formed 

 by a strong layer that is attached to the sides of the suspensory 

 ligament and sesamoid bones. Below these bones, these two 

 branches bifurcate in their turn ; whence results four branches, 

 which are inserted by pairs into the upper extremity of tiie two 

 secondary phalanges, as in the other Ruminants. 



In the Ox, tiie terminal tendon of the perforans does not 

 receive any carpal baud; this goes to the perloratus. Aliove the 

 fetlock, it divides into two branches, one ff>r each digit, which, 

 after traversing the perforatns, terminates behind the inferior 

 face of tiie third phalanx. There it is blended with the plantar 

 cushion, the inferior interdigital ligament, and a fibrous fascia 

 already noticcl in the description of that ligament This layer 

 arises from the aponeurosis covering the flexor tendons in the 

 metacarpal region ; it descends on the heels, behind and outside 

 the digits, remains united to that of the other digit by an in- 

 termediate fibrous fascia, and is attached to the enveloping 

 sheaths of the flexor tendons, as well as to tlie superior inter- 

 digital ligament. Each terminatis inferiorly, in becoming 

 united to the proper extensor of the digit, the plantar cushion, 

 the inferior digital ligament, and the deep flexor of the 

 phalanges. 



There is not, properly speaking, a phalangeal reinforcing 

 sheath ; though we may consider as such the superior fasciculi 

 of the inferior interdigital ligament (Fig. 186. 6). 



Of the three portions of the perforans in the Camel, the 



MUSCLES OF THE FOREARM OF 



THE OX (INTERNAL FACE). 



1, Anterior extensor of the 

 metacarpus ; 1', insertion of 

 it.s tendon ; 2, oblique ex- 

 tensor; 3, common extensor 

 of the digits; 3', its tendon ; 

 3", terminal bifurcation of 

 that tendon ; 4, proper ex- 

 tensor of the internal digit ; 

 4', its tendon ; 5, proper 

 extensor of the external 

 digit ; 5', its tendon; 6, its 

 branch of insertion into the 

 second phalanx ; 7, branch 

 to the third phalanx ; 8, 

 external flexor of the meta- 

 carpus ; 9, olecraniau por- 

 tion of the perforans ; 10, 

 tendon of the perforans ; 



11, tendon of the perforatus; 



12, suspensory ligament of 

 the fetlock; 13, the band 

 it furnishes to the per- 

 foratus to form the ring through which the perforans passes; 14, the external band it gives 

 off to the proper extensor of the external digit; 15, flexor brachii ; 16, anterior brachial; 17, 

 anconeus. 



24 



