278 DISEASES OF THE HOESE. 



kind, while that of the hip with the thigh bone is a perfect exhibition 

 of the latter. 



The structure whose office is to retain the articulating surfaces in 

 place is the ligament. This is usually a white, fibrous, inelastic 

 tissue; sometimes, however, it is elastic in character and yellowish. 

 In some instances it is funicular shaped or corded, serving to bind 

 more firmly together the bones to which its extremities are attached ; 

 in others it consists of a broad membrane, wholly or partially sur- 

 rounding the broad articulations, and calculated rather for the pro- 

 tection of the cavity frorn intrusion by the air than for other security. 

 This latter form, known as capsular, is usually found in connection 

 with joints which possess a free and extended movement. The 

 capsular and funicular ligaments are sometimes associated, the cap- 

 sular appearing as a membranous sac wholly or partially inclosing 

 the joint; the funicular, here known as an interarticular ligament, 

 occupying the interior, and thus securing the union of the several 

 bones more firmly and effectively than would be possible for the cap- 

 sular ligament unassisted. 



The universal need which pertains to all mechanical contrivances 

 of motion has not been forgotten while providing for the perfect 

 working of the interesting piece of living machinery which performs 

 the function of locomotion, as we are contemplating it, and nature 

 has consequently provided for obviating the evils of attrition and 

 friction, and insuring the easy play and smooth movement of its 

 parts, by the establishment of the secretion of the synovia, the vital 

 lubricant of which we have before spoken, as a yellow, oily, or 

 rather glairy secretion, which performs the indispensable office of 

 facilitating the play of the tendons over the joints and certain given 

 points of the bones. This fluid, which is deposited in a containing 

 sac, the lining (serous) membrane of which forms the secreting 

 organ, is of an excessively sensitive nature, and while it lines the 

 inner face of the ligaments, both capsular and fascicular, is attached 

 only upon the edges of the bones without extending upon their 

 length, or between the layers of cartilage which lie between the bones 

 and their articular surfaces. 



Our object in thus partially knd concisely reviewing the structure 

 and condition of the essential organs of locomotion has been rather 

 to outline a sketch which may serve as a reference chart of the gen- 

 eral features of the subject than to offer a minute description of the 

 parts referred to. Other points of interest will receive due attention 

 as we proceed with 'the illustration of our subject and examine the 

 matters which it most concerns us to bring under consideration. The 

 foundation of facts which we have thus far prepared will be found 

 sufficiently broad, we trust, to include whatever may be necessary to 

 insure a ready comprehension of the essential matters which are to 



