138 NATURAL THEOLOGY, 



are severally to move. In like manner, the mus- 

 cles which move the toes and many of the joints 

 of the foot, how gracefully are they disposed in the 

 calf of the leg, instead of forming an unwieldy 

 tumefaction in the foot itself! The obsei-vation 

 may be repeated of the muscle w^hich draws the 

 nictitating membrane over the eye. Its office is in 

 the front of the eye ; but its body is lodged in the 

 back part of the globe, wiiere it lies safe, and where 

 it encumbers nothing. 



V. The great mechanical variety in the figure 

 of the muscles may be thus stated. It appears to 

 be a fixed law that the contraction of a muscle 

 shall be towards its centre. Therefore the sub- 

 ject for mechanism on each occasion is, so to 

 modify the figure and adjust the position of the 

 muscle as to produce the motion required agree- 

 ably with this law. This can only be done by 

 giving to different muscles a diversity of configu- 

 ration suited to their several offices, and to their 

 situation with respect to the work which they 

 have to perform. On which account we find them 

 under a multiplicity of forms and attitudes ; some- 

 times with double, sometimes with treble tendons, 

 sometimes with none: sometimes one tendon to 

 several muscles, at other times one muscle to 

 several tendons. The shape of the organ is sus- 

 ceptible of an incalculable variety, whilst the ori- 

 ginal property of the muscle, the law and line of 

 its contraction, remains the same, and is simple. 

 Herein the muscular system may be said to bear 



