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8 such as Caradrina cubicularis, the pale mottled willow moth of Curtis ('Farm Insects,' p. 308), identified for me by Mr. C. G. Barrett and the Rev. J. Hellins.

If one-fourth of the young sparrows hatched in England are fed for ten days on 14 caterpillars apiece, it is easy to make a calculation of how many they would eat in a large agricultural county like Norfolk. Norfolk contains 800 parishes: say that 800 young sparrows are annually hatched in each parish; that gives us a total of 640,000 sparrows. If one-fourth of them are fed on caterpillars, we should have 22,400,000 of these destructive creatures eaten in this one county alone, every year, by sparrows. So that there is a very nice balance to adjust in a matter which the most expert observer might find difficult. On the one hand the young sparrows are fed on a great many caterpillars; on the other hand they are fed with grain, but this is mixed with weeds and other vegetable matter. Again, there is a side light in which to look at the question:—If the sparrows were dead, how many of these caterpillars would be eaten by other small birds? We may be quite sure that a considerable portion of them would not be eaten, unless chaffinches and greenfinches become more numerous than they are now; and if this