IN THE HUMAN FRAME, "65 



VI. The shoulder-hladc is, in some material respects, a 

 very singular bone ; it appearing to be made so expressly 

 for its own purpose, and so independently of every other 

 reason. (PI. X. fig. 4.) In such quadrupeds as have no 

 collar bones, which are by far the greater number, the 

 shoulder-blade has no bony communication w-ith the trunk, 

 either by a joint, or process, or in any other way. It does 

 not grow to, or out of, any other bone of the trunk. It 

 does not apply to any other bone of the trunk — (I know not 

 whether this be true of any second bone in the body, ex- 

 cept perhaps the os hyoides.) In strictness, it forms no 

 part of the skeleton. It is bedded in the flesh ; attached 

 only to the muscles. It is no other than a foundation 

 bone for the arm^ laid in^ separate, as it were, and distinct, 

 from the general ossification. The lower limbs connect 

 themselves at the hip with bones which form a part of the 

 skeleton ; but, this connection^, in the upper limbs, being 

 wanted, a basis whereupon the arm might be articulated 

 was to be supplied by a detached ossification for the pur- 

 pose, 



I. The above are a few examples of bones made re- 

 markable by their configuration ; but to almost all the 

 bones heXong joints ; and in these, still more clearly than 

 in the form or shape of the bones themselves, are seen 

 both contrivance and contriving wisdom. Every joint is a 

 curiosity, and is also strictly mechanical. There is the 

 hinge joint, and the mortice and tenon joint; each as 

 manifestly such, and as accurately defined, as any which 

 can be produced out of a cabinets-maker's shop. And one 

 or the other prevails, as either is adapted to the motion 

 which is wanted : e. g, a mortice and tenon, or ball and 

 socket joint, is not required at th« knee, the leg standing 

 in need only of a motion backward and forward in the 

 same plane, for which a hinge joint is sufficient ; a mortice 

 and tenon, or bail and socket joint, is wanted at the hip, 

 that not only the progressive step may be provided for, but 

 the interval between the limbs may be enlarged or contract- 

 ed at pleasure. Now observe what would have been the 

 inconveniency, i. e. both the superfluity and the defect of 

 articulation, if the case had been inverted ; if the ball and 

 socket joint had been at the knee, and the hinge joint 

 at the hip. The thighs must have been kept constantly to- 

 gether, and the legs have been loose and straddling. There 

 would have been no use that we know of, in being able to turn 

 G 



