356 LEAVES FROM THE 



sending a lateral slip to tlie next muscle, being inserted 

 into the third rib behind it. The fourth set passes from 

 one rib over the next. The fifth set goes from rib 

 to rib. 



Within, the apparatus is not less beautifully adjusted. 

 On the inside of the chest a strong set of muscles is attached 

 to the anterior surface of each vertebra, and passes 

 obliquely forwards over four ribs, to be inserted nearly 

 in the middle of the fifth. Then comes from each rib a 

 strong flat muscle, advancing on each side before the 

 viscera, to form the abdominal muscles, and unites in a 

 middle tendon. Thus, the lower half of each rib, which 

 is beyond the origin of this muscle, and only laterally 

 connected to it by loose cellular membrane, is external 

 to the belly of the animal, and is employed for the pur- 

 pose of progression ; while the half of each rib next the 

 spine, as far as the lungs extend, is made ancillary to 

 respiration. At the termination of each rib is a small 

 cartilage, corresponding in shape to the rib, and tapering 

 to the point. The cartilages of the opposite ribs are not 

 connected, so that when the ribs are drawn outwards by 

 the muscles, they are separated, and rest their whole 

 length on the inner surface of the abdominal scutes, to 

 which they are connected by a set of short muscles, and 

 they have also a connexion with the cartilages of the 

 neighbouring ribs by means of a set of short straight 

 muscles. 



Endowed with this aj^paratus, the seipent, when mov- 

 ing, is altered in shape, from a circular or oval form to 

 one approaching a triangular figure, the surface on the 

 ground forming the base. 



But before Sir Everard entered into this inquiry, Sir 

 Joseph Banks, with that instinctive acuteness which 

 belonged to him, had remarked, as he watched a snake 

 moving briskly along the carpet, that he thought he saw 

 the ribs come forward, in succession, like the feet of a 



