148 THE EVOLUTIONIST AT LARGE. 



to suit the higher and freer life for which the 

 insect was unconsciously preparing itself. 

 Fewer and smaller ganglia now appeared in 

 the tail segments (since no legs would any 

 longer be needed there), while more import- 

 ant ones sprang up to govern the motions of 

 the four wings. But it was in the head that 

 the greatest changes took place. There, a 

 rudimentary brain made its appearance, with 

 large optic centres, answering to the far more 

 perfect and important eyes of the future 

 butterfly. For the flying insect will have to 

 steer its way through open space, instead of 

 creeping over leaves and stones ; and it will 

 have to suck the honey of flowers, as well as 

 to choose its fitting mate, all of which de- 

 mands from it higher and keener senses than 

 those of the purblind caterpillar. At length 

 one day the chrysalis bursts asunder, and the 

 insect emerges to view on a summer morning 

 as a full-fledged and beautiful butterfly. 



For a minute or two it stands and waits 

 till the air it breathes has filled out its wings. 



