114 MECHANISM OF THE MUSCLES. 



B. So we have here the principle of an air pump. 

 How impossible to imagine any thing but intelligence, 

 when we witness such examples of philosophical 

 mechanism ! 



In the feet of aquatic birds, besides the web or 

 membrane between the toes by which they are ena- 

 bled to make a broader and more powerful stroke up- 

 on the water, another peculiarity has been less fre- 

 quently noticed, viz. that their feet are situated fur- 

 ther back than those of other birds. This enables 

 them to thrust themselves forward more directly and 

 with greater force in the water. The breast is not 

 tipped down, when the animal strikes the water be- 

 hind, because the breasts of all aquatic birds are pecu- 

 liarly broad and covered with oily feathers which ren- 

 der them so buoyant, that this position of the feet is 

 even necessary to enable the animal to dive, by means 

 of the stroke of the feet so near the hinder extremity 

 of the body. Their legs also are shorter in propor- 

 tion than usual, in consequence of which the resis- 

 tance of the water is diminished. 



MUSCLES AND TENDONS. 



A. We now come to another view of this won- 

 derful workmanship. Having surveyed the admirable 

 mechanism of the frame work, we are next to see the 

 curious machinery which the All-wise Artificer has 

 employed for putting all this apparatus in motion. 



By what means are the motions of the bones 

 performed ? 



A. By what are called the muscles and tendons. 

 Though the flesh has the appearance, at first view, of 



