T^ATURAL THEOLOGY. 125 



parts protected with peculiar care ; and that by a 

 provision in the figure of the bones themselves. 

 The nerves which supply the fore-arm, especially 

 the inferior cubital nerves, are at the elbow con- 

 ducted, by a kind of covered way, between the 

 condyls, or rather under the inner extuberances 

 of the bone which composes the upper part of the 

 arm.* At the knee, the extremity of the thigh- 

 bone is divided by a sinus, or cliff, into two heads 

 or protuberances; and these heads on the back- 

 part stand out beyond the cylinder of the bone. 

 Through the hollow which lies between the hind- 

 parts of these two heads — that is to say, under 

 the ham, between the ham-strings, and within the 

 concave recess of the bone formed by the extu- 

 berances on each side — in a word, along a de- 

 file, between rocks, pass the great vessels and 

 nerves which go to the leg.f Who led these ves- 

 sels by a road so defended and secured? In the 

 joint at the shoulder, in the edge of the cup which 

 receives the head of the bone, is a notch, which is 

 joined or covered at the top with a ligament. 

 Through this hole, thus guarded, the blood-vessels 

 steal to their destination in the arm, instead of 

 mounting over the edge of the concavity.J 



III. In all joints, the end of the bones, which 

 work against each other, are tipped with gristle. 

 In the ball and socket-joint, the cup is lined and 



* Ches. Anat. p. 255, ed. 7. 

 t Ibid. p. 35. I Ibid, p. 30. 



11* 



