30(5 THE TROPICAL WORLD. 



faculty which is still further increased by the great mobility of 

 the spondyli of the backbone. Between the ribs and the broad 

 transverse scales or plates which exist on the belly of all such 

 serpents as move rapidly, we find numerous muscles connecting 

 them one with another, and thus, amply provided with a whole 

 system of strong pulleys and points of attachment, the reptile, 

 bringing up the tail towards the head, by bending the body 

 into one or more curves, and then again resting upon the tail 

 and extending the body, glides swiftly along, not only upon 

 even ground, but even sometimes from branch to branch, as 

 the smallest hold suffices for its stretching out its body at a 

 foot's length into the air, and thus reaching another sallying 

 point for further progress. 



The anatomy of the serpent's jaws is no less remarkable than 

 the mechanism of its movements. In spite of their proverbial 

 wisdom, snakes would not be able to exist unless they were 

 able to swallow large animal masses at a time. For, however 

 rapid their motions may be, those of their prey are in general 

 still more active, and thus they are obliged to wait in ambush 

 till a fortunate chance provides them with a copious meal. 

 The victim is often much more bulky than the serpent itself, 

 but still, without tearing it to pieces, it is able to engulph it 

 in its swelling maw. For the two halves of its lower jaw do 

 not coalesce like ours into one solid mass, but are merely con- 

 nected in front by a loose ligament, so that each part can be 

 moved separately. The bones of the upper jaw and palate are 

 also loosely attached or articulated one with the other, and 

 thus the whole mouth is capable of great distension. By this 

 mechanism, aided by the numerous sharp teeth, which are so 

 many little hooks with the point curved backwards, each side 

 of the jaws and mouth being able to act as it were indepen- 

 dently of the other, alternately hooks itself fast to the morsel, 

 or advances to fasten itself farther on in a similar manner, and 

 thus the reptile draws itself over its prey, somewhat in the 

 same way as we draw a stocking over our leg, after having first, 

 by breaking the bones, fashioned it into a convenient mass, and 

 rendered its passage more easy by lubricating it with its saliva. 

 Slowly the huge lump disappears behind the jaws, descends 

 lower and lower beneath the scales, which seem ready to burst 

 asunder with distension, and then the satisfied monster coils 



