AUGUST. 129 



the advantages which we derive, however, from our 

 variable climate is comparative immunity from 

 " plagues " of caterpillars, though the sequence of 

 mild winters and fine summers that we have enjoyed 

 of late brought us very near to several. Curiously 

 enough, too, the very caterpillars which possess the 

 power of becoming upon occasion a devastating 

 pest are usually those which seem most helpless and 

 conspicuous, and are the offspring of sluggish and 

 easily detected moths. The reason is, of course, that 

 they are " protected," either by stinging hairs or acrid 

 taste, from most insect-eating creatures, and so, when 

 their real enemy, the weather, spares them for several 

 successive seasons, there is no check upon their 

 multiplication. As, moreover, they reproduce their 

 kind a hundredfold in each generation, the fourth 

 mild year may see a million caterpillars descended 

 from each female moth. 



THE BROWN-TAIL PLAGUE. 



Once, towards the end of the eighteenth century, 

 the brown-tail moth scourged Europe, including the 

 British Isles. Ordinarily the brown-tail moth a 

 good-sized, snow-white moth, with a dense paint- 

 brush tail of rich brown hairs is by no means 

 abundant ; but it is very easily discovered, and seems 

 always too sleepy, when caught, to do anything but 

 lie on its back with its legs in the air. Even when 

 provoked to fly, it moves so slowly and steadily that 

 you can easily knock it down again. Its caterpillars, 

 too, are conspicuously handsome creatures, of black, 

 red, and white, with tufted hairs, and they sit by 



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