MUSCLES OF THE POSTERIOR LIMBS. 297 



The pectineus repeats the anterior branch of the pectineus of the Horse. It is inserted* 

 below, into the internal bifurcation of the linea aspera of the femur. 



The first adductor corresponds to the posterior branch of the pectineus of Solipeds. 

 It is represented by a voluminous muscular mass, which arises from the spine of the 

 pubis and terminates on the middle third of the linea aspera. 



The second or small adductor corresponds to the muscle of the same name in animals. 

 It is insert d into the same points as the preceding. 



The third or great adductor is attached, above, to the ischiatic tuberosity and to the 

 whole of the lower branch of the ischium by aponeurotic fibres. It afterwards divides 

 into two branches: the external branch, entirely muscular, is fixed into the entire 

 interspace of the liuea aspera ; the internal branch gives rise to a tendon which goes to 

 the inner condyle of the femur. Between these two branches is found, as in the Horse, 

 the ring of the adductors, in which pass the large vessels of the thigh. 



The square crural of Man is nearly horizontal, as it is attached, inwardly, to the 

 external border of the ischium, and outwardly, between the great and small trochanters. 



The internal obturator and gemelli resemble those of the Dog. 



MUSCLES OF THE LEG. 



These muscles, nine in number, are grouped around the two principal 

 bones of the leg, so as almost to completely envelop them, leaving only the 

 internal face of the tibia uncovered. Like those of the fore-arm, they form 

 two particular regions : an anterior and a posterior ; and they are sheathed in 

 common by the tibial aponeurosis^ a very solid fibrous covering which in every 

 respect corresponds to the antibrachial aponeurosis. 



TIBIAL APONEUROSIS. 



This aponeurosis is formed of several superposed layers which are 

 intimately united, and receives, superiorly, the insertion of the long vastus, 

 the semitendinosus, and the short adductor of the leg, which may be con- 

 sidered as its tensor muscles. 



It is continued, inferiorly, over the tarsus and the metatarsal region, in 

 becoming singularly attenuated, and in covering the fibrous bands which 

 bind and retain the anterior tibial muscles in the bend of the hock. Its 

 external surface is separated from the skin by a very thin cellulo-fibrous 

 expansion ; its internal face furnishes special and very firm sheaths around 

 the majority of the tibial muscles. 



The tibial aponeurosis is attached to the internal surface and crest of the 

 tibia, as well as to the summit of the calcis. The latter attachment takes place 

 by a thick fibrous band, whose singular and complicated disposition has not 

 yet been exactly described. It is situated in front of the tendon of the 

 hock, or between that tendon and the deep layer of the posterior tibial 

 muscles. By its borders, it is continuous with the tibial aponeurosis or 

 fascia. Superiorly, it adheres most intimately to the perforatus tendon, near 

 the point where the latter originates ; there it sends off a thick fasciculus which 

 descends to the gastrocnemius tendon. Below this, it appears to divide into 

 two branches, an external and internal, which are united to the calcanean cap 

 of the perforatus tendon, and are attached to the sides of the calcis in such a 

 manner, that near its insertion the gastrocnemius tendon is found to be 

 enveloped by a complete fibrous sheath, formed partly by the perforatus 

 tendon and partly by the band just described. This latter, therefore, con- 

 stitutes a strengthening apparatus for the tendon of the hock : a structure 

 noticed by Girard, who made it a branch of insertion of the semitendinosus ; 

 and not without reason, perhaps, because it arises from the tibial aponeurosis, 

 which, in part at least, is itself derived from the semitendinosus muscle. 



Preparation of the Muscles of the Leg. Separate the limb from the trunk by sawing 



