INSECTS' EGGS 133 



of modern science now say: "That the atmo- 

 sphere is freighted with myriads of insects' eggs 

 that elude our senses, and that such eggs, when 

 they meet with a proper bed, are hatched in a 

 few hours into a perfect form, is clear to any one 

 who has attended to the rapid and wonderful 

 effects of what in common language is called a 

 1 blight ' upon plantations and gardens ; " or assert 

 that, the honey-dew which is produced by the 

 aphides "is a peculiar haze or mist loaded with 

 poisonous miasm." Yet both of these statements 

 were gravely put forward by an eminent naturalist 

 in 1829, in connection with the common, but un- 

 pleasant, phenomenon of the sudden appearance 

 of small life in vast numbers where, from man's 

 point of view, it was not wanted. Such errors 

 are impossible now, and one needs not much 

 science to be aware that the mother blue-bottle 

 or "blow-fly," scents the meat afar off, and with 

 maternal instinct hastens to lay her eggs upon it 

 that her young may thrive, the young grubs 

 appearing more or less rapidly according to the 

 temperature. 



The common house-fly in like manner usually 

 discovers material in which her young may undergo 

 their metamorphoses ; and sometimes she selects 

 such substances as ripe fruit, sweet cakes, or even 

 brcac!, as a suitable situation for her curious white 



