70 LOCOMOTION. [CHAP. III. 



through which the force has acted, have escaped. Thus, the malleoli 

 are often dragged off hy twists of the foot acting on those processes 

 of bone through the lateral ligaments of the joint. It is entirely 

 devoid of contractility or irritability; and its sensibility is very 

 low, so much so that tendons hanging out of a wound have been 

 cut without the patient being aware of it. 



Vessels and Nerves. White fibrous tissue contains few vessels ; 

 they are small, and follow for the most part the course of the bun- 

 dles of the tissue ; they appear more numerous in the dura mater, 

 and in periosteum, than in other parts. The presence of nerves, 

 and their mode of subdivision, have not as yet been satisfactorily 

 demonstrated anatomically ; we infer their existence from the tissue 

 manifesting sensibility in some forms of disease. 



Chemical Composition. The flexibility of fibrous tissue is owing 

 to its containing a small proportion of water. A tendon, ligament, 

 or fibrous membrane, will dry readily ; it then becomes hard and 

 rigid ; it resists the putrefactive process when not kept moist, and 

 even then putrefies less readily than the softer textures. Acetic 

 acid causes it to swell up, instantly removes its peculiar ap- 

 pearance of wavy fibres, and displays some broken elongated 

 corpuscles, which are probably the remains of the nuclei of the 

 development-cells. Gelatine may be extracted in considerable 

 quantity from white fibrous tissue by boiling, and it would appear 

 to constitute its chief proximate principle. 



Of the different Forms of White Fibrous Tissue. A. Ligaments. 

 Ligaments are connected with joints. They pass in determinate 

 directions from one bone to another, and serve to limit certain move- 

 ments of the joint, while they permit others. They, therefore, con- 

 stitute an extremely important part of the articular mechanism in 

 preserving the integrity of the joint in its various movements. 

 There are three principal kinds of articular ligaments. 1. Funi- 

 cular, rounded cords of white fibrous tissue, of which we may give 

 as examples the external lateral ligament of the knee-joint, the 

 perpendicular ligament of the ankle-joint, &c. : 2. Fascicular, 

 flattened bands, more or less expanded ; ex. internal lateral liga- 

 ment of the knee-joint, lateral ligaments of the elbow-joint, an- 

 terior and posterior ligaments of the wrist-joint, and, indeed, the 

 great majority of ligaments in the body : 3. Capsular ; these are 

 barrel-shaped expansions, attached by their extremities around the 

 margin of the articular surfaces composing the joint, and forming 

 a complete but a loose investment to it, so that its movements 

 are not particularly restricted in one direction more than another. 



