92 OF THE MUSCLES. 



Ligaments are dense, white, fibrous substances, of gi'eat 

 tenacity ; either cord-hke as tendons, or expanded into 

 more flat layers. Under still greater tenuity, ligament 

 becomes a common membrane in every part of the body, 

 under the name of fascia ; but it is more particularly appro- 

 priate to bones ; hence it is generally described with them. 

 Ligaments have usually but little inelasticity ; when however 

 they are of a yellow colour they are highly elastic ; as witness 

 the ligament of the neck ; the ligamentous substance cover- 

 ing the abdominal muscles, &c. Some of them partake of 

 the nature of cartilage, and are hence called cartilaginous 

 ligaments ; being hard and little vascular. 



The synovia is a fluid popularly, but erroneously, termed 

 joint-oil; for it is not unlike the white of an egg, and is 

 secreted by the fine membrane lining the interior of joints. 

 Its lubricating use is very great ; for without it, the attrition 

 between the articulated ends of bones would painfully inter- 

 fere with motion : but by this slippery medium they readily 

 slide over each other, without pain or difficulty. This fluid 

 may be secreted in undue quantities ; and then forms dropsy 

 of the joint ; which is not, however, frequent in the horse, 

 excepting in the hock-joint, when it is called bog spavin. 

 Bursal dropsy, under the name of wind-gall, is sufficiently 

 common. 



SECTION IX. 



DESCRIPTION OF PLATE II. 



THE MUSCLES OF THE HORSE ; SHOWN BY DEPRIVING THE 

 ANIMAL OF HIS SKIN, AND THE GREATER PART OF THE 

 PANNICULUS CARNOSUS. 



1, Levator anglioris ; 2, levator labii superioris ; 3, re- 

 tractor labii superioris ; 4, zygomaticus ; 5, caninus ; 6, 

 buccinator ; 7, retractor labii inferioris ; 8,8, the tracheal 

 portion of the panniculus carnosus, which, reflected over the 

 masseter externus muscle, ultimately extends to the mouth, 

 and there forms the retractor anglioris ; the portions turned 

 back in the engraving denote whence the thin muscle has 



