242 THE WALKS ABROAD OF 



insects under the bark and in the wood of trees, where 

 they are carrying on their ravages unseen. The cuckoo 

 attacks hairy caterpillars that other birds refuse to 

 swallow ; the European rollers, grasshoppers and 



COAST BIED&. 



locusts ; the hedge-sparrows, snails and larvee, as- 

 sisted in this task on the banks of the rivers by the 

 godwits, sandpipers, snipe, and indeed by the waders 

 generally. 



"Pursuing another system of tactics, the swallow, 



