THE REASON WHY. 223 



' That which *.o born of the flesh is flesh ; and that which is born of the Spirit 

 is spirit." JOHN in. 



939. What are tendons ? 



Tendons are long cords, of a substance similar in its nature to 

 cartilage, by which the muscles are attached to the lone*. 



Fig. 56. SHOWINO A BALL AND SOCKET JOINT, AND THE MANNER IH WHICH 

 LIGAMENTS ABB EMPLOYED TO HOLD BONES IN THEIK POSITIONS. 



A. The ball, or head of the thigh bone. 



B. The socket, showing the ligament iu the socket, which holds the head of 

 the bone in its place, but allows it free motion. 



C. Ligaments tied from bone to bone, giving firmness to the parts. 



940. Why are tendons used to attach the muscles to the 

 tones ? 



Because, by this arrangement, the large muscles by which the 

 extremities are moved, may be placed at some distance from the 

 bones upon which they act, and thus the extremities, instead of 

 being large and clumsy, are small and neat. 



941. How many muscles are there in the human body ? 

 There are about four hundred, and forty-six muscles that 



have been dissected and described, and the actions of which are 

 perfectly understood. But there is probably a much larger number 

 of muscles, and of compound actions of muscles, than the skill of 

 man has been able to recognise. 





