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LIFE, IN ITS HIGHER FORMS. 
the ground and becomes a fixed point from whence to set 
out anew. This motion is beautifully seen when a Snake 
is climbing over an angle to get upon a flat surface. When 
the animal is moving, it alters its shape from a circular or 
oval form to something approaching a triangle, of which 
the surface on the ground forms the base. The Coluber 
and Boa having large abdominal scuta, which may be com 
sidered as hoofs or shoes, are the best fitted for this kind 
of progressive motion An observation of Sir 
Joseph Banks, during the exhibition of a Coluber of unusual 
size, first led to this discovery. While it was moving 
briskly along the carpet, he said he thought he saw the 
ribs come forward in succession, like the feet of a cater- 
pillar. This remark led me to examine the animal’s motion 
with more accuracy, and, on putting the hand under its 
belly, while the Snake was in the act of passing over the 
palm, the ends of the ribs were distinctly felt pressing upon 
the surface in regular succession, so as to leave no doubt 
of the ribs forming so many pairs of levers, by which the 
animal moves its body from place to place.” 
Many of the Serpents habitually live among the branches 
of trees, and most species can climb the smooth trunks with 
facility; not, however, by encircling the branch or bole in 
spiral coils, as artists who probably never saw a Snake in 
motion ridiculously represent them, but by a direct upward 
gliding, the body extended nearly in a straight line. 
As all the Serpent tribes arc carnivorous, and almost all 
feed on living active animals, often of much greater bulk 
than the diameter of their own mouths, while yet they 
invariably swallow their prey entire, it becomes a problem 
of interest how this is effected. They arc fitted for their 
