THE MUSCLES OF THE HORSE. 



301 



not borne upon any distinct neck, whicli articulates almost 

 wholly with the naviculare, presenting only a very small facet 

 to the cuboid. 



The naviculare and the ecto-cunei- 

 forra are peculiarly broad and flattened 

 in form (Fig. 93 A, 94 B). 



The metatarsus and digits repeat the 

 arrangements of the fore-limb ; but the 

 principal metatarsal is more slender in 

 its proportions, and is flattened from 

 side to side rather than from before back- 

 ward (Fig. 93 B, 94 B). 



As might be expected, the principal 

 peculiarities of the muscular system of 

 the Horse are to be observed in the 

 limbs. 



The serratus magnus and the levator 

 anguli soapulce (which really form one 

 muscle), together with a sterno-soapur 

 laris, form the great sling already men- 

 tioned, by which the weight of the fore- 

 part of the body is transmitted to the 

 anterior extremities. The power of 

 abduction is hardly needed by a purely 

 cursorial animal; hence the deltoid is 

 reduced to its scapular portion, which is 

 very small. On the other hand, the 

 pro- and re-tractors, the flexors and ex- 

 tensors, are well developed. The supra- ' 

 and infraspinatus are large. There is 

 a great cephalo-humeralis, answering to 

 the clavicular portions of the human 

 sternomastoid and of the deltoid, which 

 run into one another, in consequence of 

 the total absence of the clavicle. The 

 anterior portion of the sternomastoid is 

 fixed to the mandible, and thus becomes 

 " sternomaxillary." 



The latissimus dorsi and teres mus- 

 cles are very large, as are the flexors and extensors of the 

 antibrachium. 



The supinators and pronators are wanting ; but there ia 

 a distict extensor ininimi digiti, the tendon of which unites 

 with that of the extensor communis. Radial and ulnar ex- 



Fro. 100.— A, Left femur of a 

 Horse, posterior vr-mt. — 



I. Head. 2. Great tio- 

 chanter. 3. Thii-d tio- 

 chanter. 4. Lesser tro- 

 chanter. 5. Pit for round 

 ligament. 10. Fossa. 



II. Condyles. 



