PERSONAL APPEARANCES IN HEALTH AND DISEASE. I 7 



joints, which are of various forms and construction in 

 accordance with the movements they have to subserve. 

 Essentially, a joint consists in the two ends 'of the bones 

 which enter into its formation, and which are covered by a 

 layer of cartilage, a sac, secreting fluid which bathes the 

 surfaces of the cartilages, and in fibrous bands or ligaments 

 protecting these structures, and serving to keep the bones 

 in apposition and to limit their movements. The expanded 

 ends of the bones entering into the joints add to the 

 diversity of the form of the body, and alteration in these 

 joints themselves gives rise to conspicuous deformities. 



The Muscles. The skeleton, bound together and com- 

 pacted by the ligamentous structures, is clothed with 

 muscles, which are structures of flesh endowed with the 

 power of contracting, and by their contraction pulling on 

 the bones to which they are attached, and thus subserving 

 the motion of the body. According to their develop- 

 ment, so do these muscles play a large part in producing 

 the outlines of the body, and their bold configuration is 

 well reproduced in the sculptures of antiquity. Those 

 muscles which are most wanted for the support of life, 

 and for locomotion, are the most developed, e.g. those 

 of the lower limbs. 



Besides contributing largely to the mere contour of the 

 frame, the muscles have an important part to play in 



