722 



SOLIPEDA. 



spreads downwards over the fascia lata to the 

 hind leg. 



In describing the other parts of the mus- 

 cular system, it will be necessary to divide 

 them into their appropriate regions, and in 

 so doing, we shall follow the arrangement 

 usually adopted in describing the human sub- 

 ject, beginning with the 



Proper muscles of the spine. The long 

 muscles of the spine, viz. the spirialis and 

 semi-spinalis dorsi, longissimus dorsi and sa- 

 cro-lumbalis present a disposition very simi- 

 lar to what occurs in the human subject. 



The spinalis dorsi takes its origin from the 

 spinous processes of the lumbar and posterior 

 dorsal vertebrae, as well as from the broad 

 fascia of the loins, and running forwards is in- 

 serted by distinct tendons into the spines of 

 the anterior vertebrae of the back. Its con- 

 tinuation, the spinalis cervicis, is in the horse 

 of great strength and importance: its origin 

 commences from the second spine of the 



back, which origin is continued for about one 

 third of the way .down that spine towards 

 its root : it arises likewise from the third 

 dorsal spine and the ligamentum nuchse ; from 

 these origins it runs forward to be implanted 

 by strong and distinct tendons into the spines 

 of the anterior cervical vertebrae. 



The longissimus dorsi is situated immedi- 

 ately external to the spinalis, taking its origin 

 from the common mass of muscle that arises 

 beneath the lumbar fascia, as well as from the 

 spinous processes of the loins and sacrum, 

 whence it runs forward to be inserted by a 

 double set of tendons into the transverse pro- 

 cesses of the loins and back, and also into the 

 posterior ribs near their angles. Its continua- 

 tion, the transversalis colli y is likewise of con- 

 siderable strength, but offers nothing worthy 

 of remark. 



The sacro-lumbalis arises, in conjunction 

 with the latissimus dorsi, from the back of 

 the sacrum, and also by flat tendons about 



Fig. 501, 



Myology of the Horse. (After Stubbs.) 



Head. n, Levator anguli oris ; o, orbicularis oris ; t, anterior dilator of the nostril ; w, massetcr ; k, 

 septum narium ; 4, vena angularis. 12. Anterior cartilage of the external ear. 



Neck. a, Coraco-hyoideus ; g, transversalis cervicis ; I, trachelo-mastoideus, or complexus minor ; m, 

 complexus ; y, the longus colli. 



Shoulder. c, Triceps extensor cubiti ; k, tendon of the biceps flexor cubiti. 



forearm and anterior extremity. a,b,c, Extensor carpi radialis; k, extensor digitorum communis ; q, 

 analogue of the extensor minimi digiti ; 6, 9, ligaments ; t, vena plantaris interna ; M, nervus plantaria 

 internus. 



Trunk. d, serratus minor posticus; h, serratus major posticus; I, serratus major anticus; o, external 

 intercostals ; p, internal intercostals ; q, rectus abdominis ; x, obliquus internus. 



Hinder extremity. b, glutams medius; h, rectus femoris ; n, vastus externus; u, w, 21, 26, 24, extensor 

 digitorum pedis ; 6. plantaris and gastrocnemius. 



