ANIMAL ORGANIZATION. 93 



ness. In a word, they possess all the qualities that 

 can be desired in a rope. It will hardly be cre- 

 dited how great a force is required to stretch, or 

 rather rend asunder, a ligament ; for it will not 

 yield in any sensible degree until the force is in- 

 creased so enormously as at once to dissever the 

 whole contexture of its fibres. Nothing can be 

 more artificially contrived than the interweaving 

 of the fibres of ligaments ; for they are not only 

 disposed, as in a rope, in bundles placed side by 

 side, and apparently parallel to each other : but, 

 on careful examination, they are found to be tied 

 together by oblique fibres curiously interlaced, in a 

 way that no art can imitate. It is only after long- 

 maceration in Avater, that this complicated and 

 beautiful structure can be unravelled. 



The mechanical properties of these fibrous struc- 

 tures, which are strictly inextensible ligatures, 

 render them applicable to purposes of connexion 

 where motion is to be restrained. Many cases, 

 however, occur, in which a substance is wanted, 

 uniting great compactness and strength with a con- 

 siderable degree of elastic power. For this purpose 

 a different texture is fabricated, consisting of twisted 

 fibres, which impart this required elasticity. Such 

 is the structure of the elastic ligmnents of animals, 

 which are very generally employed for the support 

 of heavy parts that require being suspended. An 

 instance occurs in quadrupeds, in that strong liga- 

 ment which, as we shall find, passes along the back 

 and neck to be fixed to the head, and to support its 

 weight when the animal stoops to graze. This, the 

 ligamenUmi nuchce, as it is termed, is capable of 

 great extension, and by its elasticity reacts with 



