872 



THE MUSCLES. 



Differential Characters in the Muscles of the Leg in the other Animals. 

 1. Anterior Tibial Region. 



A. Ruminants. 



Fi^. 205. 



external muscles of the leg of 

 the ox. 



1, Originating tendon of the muscle which 

 represents the anterior extensor of the 

 phal.inges and the flexor metatarsi in 

 the horse ; 2, its flexor fasciculus ; 5, 

 that which forms the common extensor 

 of the digits ; 5', the tendon of this 

 fasciculus ; 6, its terminal bifurcation ; 

 3, the long lateral peroneus; 3', its 

 tendon; 4, origin of the anterior tibial 

 (the muscular portion of the flexor 

 metatarsi in the horse) ; 7, proper ex- 

 tensor of the external digit (short 

 lateral peroneus); 8, its tendon ; 9, its 

 insertion into the second phalanx ; 10, 

 its insertion into the third phalanx ; 11, 

 external belly of the gastrocnemius ; 

 ir, its tendon ; 12, soleus; 13, tendon 

 of the perforatus ; 14, perforans ; 14', 

 its tendon; 15, suspensorj' ligament of 

 the fetlock; 16, the band it gives off 

 to the perforatus tendon ; 17, that 

 which it sends to the proper extensor 

 of the external digit 



Among these animals, the Ox presents: 



1. A complex muscle, which is represented in the 

 Horse by the anterior extensor of the phalanges, and 

 the tendon of the flexor metatarsi. Single at its 

 superior extremity, which begins by a tendon arising 

 from the digital fossa situated between the trochlea 

 and the external condyle of the femur (Fig. 205, 1), 

 this muscle comprises in its middle part three fleshy 

 divisions, which are terminated inferiorly by tendons. 



One of these divisions, situated in front of, and 

 within the other two, has its tendon prolonged to the 

 extremity of the principal metatarsal bone, and is also 

 inserted into the cuneiform bones. It is a flexor of 

 the metatarsal region, and replaces the tendon which 

 performs this function in Solipeds (Fig. 205, 2). 



The second, placed external to the preceding, con- 

 stitutes a common extensor of the digits, the tendon of 

 which cumports itself exactly like that of the anterior 

 limb (Fig. 205, 5, 5', 6). 



The third, concealed by the other two, forms the 

 proper extensor of the internal digit, and resembles its 

 fellow in the fore extremity. 



2. An anterior tibhd muscle (muscular portion of 

 the flexor metatarsi of the Horse). It is a triangular, 

 muscular body, lodged in the antero-external fossa 

 of the tibia, into the upper part of wliich it is in- 

 serted, and is succeeded by a tendon that commences 

 towards the middle of the tibia. This tendon passes 

 through a ring pierced iu the tendon of the muscle 

 that represents the tendinous portion of the flexor 

 metatarsi ; it then deviates inwards, and is fixed into 

 the cuneiform bones and superior extremity of the 

 principal metatarsal bone (Fig. 205. 4). 



3. A proper extensor of the external digit (lateral 

 extensor of the phalanges in Solipeds, the peroneus 

 brevis lateralis in Man), the fleshy body of which is 

 altogether similar to that of the analogous muscle 

 in the Horse, and is terminated by a long tendon 

 which resembles that of the proper extensor of the 

 internal digit (Fig. 205, 7, 8, 9, 10). 



4. A muscle which represents the peroneous hngtis 

 in Man, and of which in Solipeds there is not a trace. 

 This muscle commences by a short, conical, muscular 

 body in front of the supero-external tuberosity of the 

 tibia, and terminates by a long tendon, the direction 

 of which is as follows : included at first, like the 

 muscular portion, between the proper extensor of the 

 external digit and the triple muscular fasciculus 

 already described, it arrives on the outside of the 

 tarsus, passes through the fibrous groove of the proper 

 extensor, where it is enveloped by a special synovial 

 membrane, passes over the latter in slightly crossing 

 its direction, and is inflected at first backwards, then 

 outwards, by insinuating itself underneath the ex- 

 ternal tibio-tarsal ligament, and the calcaneo-meta- 

 tarsal and the posterior tarso-metatarsnl lijjaments, 

 which retain it in a chaimel on the inferior face of 



18, the pedal 

 muscle ; 19, the insertion of the biceps femoris on the patella, and its external ligament. 



