14 PERSONAL APPEARANCES IN HEALTH AND DISEASE. 



free from anterior attachments, and are hence called 

 " floating ribs." 



The bones of the upper extremity consist in the large 

 single arm-bone or humerus, the upper extremity of 

 which is rounded and fits into a socket in the blade-bone 

 or scapula a flattened bone, which rests over the upper 

 ribs on the back, and can move over them for some 

 distance ; a curved bone forming a prominent feature at 

 the top of the chest the " collar-bone " passes from the 

 scapula to the sternum. The arm-bone is joined at the 

 elbow by a hinge joint with the bones of the forearm, 

 or rather with the ulna, which alone enters into the 

 elbow-joint. The ulna is thicker at its upper extremity, 

 where it forms the prominence of the elbow, than at its 

 lower ; its fellow, the radius, on the outer or thumb 

 side of the forearm, articulating with the ulna above, 

 and capable of rotation, alone bears the wrist. Then 

 comes the wrist-joint and a series of small bones, eight in 

 all, forming the wrist ; to these succeed five long bones 

 forming the framework of the hand, and upon them are 

 articulated the finger-bones or phalanges, of which there 

 are in all fifteen, three to each finger and two to the thumb. 

 Each successive lower segment is smaller than the upper, 

 the terminal phalanx being expanded at the extremity 

 where the nail is borne. The length of the fingers depends 

 upon the development of these bones, and the long, taper- 



