ANIMAL ORGANIZATION. 107 



be desired in a rope. It will hardly be credited 

 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 increased 

 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 dis- 

 posed, 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 water, that this complicated 

 and beautiful structure can be unravelled. 



The mechanical properties of these fibrous 

 structures, which are strictly inextensible liga- 

 tures, render them applicable to purposes of 

 connexion where motion is to be restrained. 

 Many cases, however, occur in which a sub- 

 stance is wanted, uniting great compactness and 

 strength with a considerable 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 ligaments 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 ligament which passes along the 



