2 Our Bird Friends. 



layer of winged insects between them. I have seen 

 huge oak trees in England denuded of their leaves 

 by small caterpilJars that were hanging by their 

 line silken threads from every bough, branch, 

 and twig. In America, some years ago, a mighty 

 host of caterpillars bade defiance for days together 

 to a railway train by crossing the line upon 

 which it was advancing in such prodigious numbers 

 that their crushed bodies made the metals too 

 greasy for the engine wheels to grip them, and after 

 the contents of the sand-boxes had given out they 

 simply slipped round and round Avithout making 

 any progress. 



In most countries the stock topic of conversation 

 amongst acquaintances is the weather, but in South 

 America, instead of remarking, "It's a fine morning 1" 

 they salute each other with some reference to insect 

 life, such as, "How are you with regard to mos- 

 quitoes ? " Humboldt, the great traveller, records the 

 fact that his boatmen got so used to slapping each 

 other's bare backs, in order to drive away the 

 mosquitoes, that the poor fellows used to keep on 

 slapping even whilst they were asleep. I have my- 

 self seen gnats rise in such clouds from tree tops 

 on a sultry summer's evening that they looked like 

 pillars of smoke, and I once witnessed a number of 

 hay harvesters absolutely driven from a field by 

 midgets. Not long ago, I was compelled to aban- 

 don a small row-boat, which I was dragging through 

 some deep heather growing on a piece of land dividing 



