94 THE MEANING OF EVOLUTION 
an interesting variation of conditions to which it must 
adapt itself. The means by which it accomplishes this 
will be clearer if the mouth of the grasshopper be 
compared with our own. Our lips are upper and 
lower, but the grasshopper has a front lip and a hind 
one. The broad front lip is easily seen at the for- 
ward side of the mouth. Just behind it, serving the 
purpose of our teeth, is a pair of hard jaws with 
horny tips upon them, which serve to break small 
pieces from its food. While our jaws and those of all 
other backboned animals work up and down, so that 
we may be said to have an upper and lower jaw, the 
grasshopper and all of his insect, crab, or spider re- 
lations, which have jaws at all, have them right and 
left, and they work from side to side. Behind these 
harder mouth parts is found a pair of softer jaws, 
each of which has on it a little finger-like feeler. 
With this pair the insect holds its food while the hard 
jaws break it to pieces. The hind lip follows, and is 
also provided with short finger-like feelers. The feel- 
ers on the hind lip and on the soft jaw are necessary 
because the eyes are so placed as not to be able to see 
what goes into the mouth, hence the insect must make 
up for the loss of sight by the addition of touch. The 
same type of mouth as the grasshopper has will be 
found among the beetles. Here the males sometimes 
have the hard jaws so enormously enlarged that they 
