NATURAL THEOLOGY. 99 



double one hand into the shape of a ball, and turn 

 it round in the other, this would resemble the joint at 

 the upper extremity of the arm. Now, the hinge 

 joint, we can see, does well at the elbow ; but at the 

 shoulder, it would have deprived us of half the use 

 of our arms. It must have kept them always at the 

 same distance from the body ; they would have 

 swung forever in one particular line, like the arms of 

 a loom. 



The provision for uniting the arm to the body is in 

 some material respects a very remarkable structure. 

 It can only be appreciated, as it deserves, by one 

 who will be at the pains to reflect upon all the pos- 

 sible modes in which the object could be effected in 

 which the arm could be attached by a firm and sub- 

 stantial joint. The ribs are evidently too slender and 

 weak to sustain a great pressure at a single point no 

 larger than the head of the arm bone. The arm, 

 therefore, could not be jointed to a rib. It would 

 have been forced into the body by the first violent ef- 

 fort. The spine would have been still more endan- 

 gered. But no other bone remains in that neighbor- 

 hood, belonging to the united frame of the trunk ; the 

 collar bone and breast bone excepted, which are evi- 

 dently out of the question. We have here an obvi- 

 ous difficulty, and it is wonderful to see how it has 

 been surmounted. A broad, flat bone, called the sca- 

 pula or shoulder-blade, is spread outside a number of 

 ribs together, against which the arm rests, and 

 to which it is attached and whereby the pressure is 

 so much extended as to occasion no danger to the 



