84 THE STUDY OF ANIMAL LIFE 



greatly minimised. Then we find other living 

 things are provided with a combination of springs 

 and curves. We find this, for example, in some 

 Mnds of caterpillars. 



There is also another provision made whereby 

 some kinds of caterpillars can, by means of glutin- 

 ous threads, drop from twig to twig when in search 

 of their food; and if by misadventure they are 

 thrown or fall to the earth, they in their fall 

 assume a curved shape, and having hairs or 

 bristles all over their bodies supplied with a beau- 

 tiful arrangement of sensitive nerves, and which 

 enables them to instantly curve the points of the 

 bristles, this gives them a protection from injury 

 when falling to the ground. The Hedgehog is an 

 example in a way, but not a good example, as its 

 spines are only a partial preventative from injury 

 when falling, being for its size one of the heaviest 

 of animals. It is more suited for short falls or 

 rolling down inclines. The Hedgehog, if dropped 

 from any considerable height, would fare badly, I 

 am afraid. 



Some kinds of Spiders have a way of folding 

 their legs around their bodies, and presenting a 

 number of joints, which gives them immunity 

 from injury when falling. Some insects have 

 scales and plates on their bodies. In the one case 

 the hard rounded plates are their protection; in 

 the other their having the power of erecting and 



