CHAPTER THE SIXTH, 
ENEMIES OP THE CATERPILLAR. 
It is a good thing for ns, that the caterpillars 
have so many enemies to thin their numbers, 
and keep them within hounds. The birds that 
gladden our ears in spring, depend principally for 
their support on an abundant supply of cater¬ 
pillars, and wage incessant war upon them. 
If the caterpillars were to fail, the birds would be 
very badly off indeed. One brood of sparrows 
will devour, it is said, as many as three thousand 
in a week. The cuckoo picks them off the leaf, 
one after the other, by dozens, and that in spite 
of all their contrivances to hide themselves. Even 
the great caterpillar is not safe in the heart of 
the tree. Every now and then, the woodpecker 
comes tapping with his long bill, and listens to 
hear if the wood sounds hollow. If it does, he 
knows his prey is within; and inserting his bill, 
