586 General Notices. 



may be examined every day without in the least interfering with the 

 trap. 



I have thus hastily put together the above particulars, which, if thought 

 worthy a place in the Gardener's Magazine, are quite at your service. Be- 

 fore I conclude, however, I will just observe, that my friend had a mouse- 

 trap on the same principle, only on a smaller scale, and of lighter materials, 

 which answered extremely well. The mice dropped through the trap into 

 a little cistern of water beneath. I am, my dear Sir, &c. — S. Taylor. 

 Country Times Office, 139. Fleet Street, May 20. 



■■ The rapid Generation of Insects, §c. — Sir, I take the liberty of submitting 

 to you an idea which has struck me upon the subject of the very rapid ge- 

 neration of insects in the spring, otherwise called blight; and particularly of 

 those insects called A'phides. It is well known, that in a few days, or even 

 hours, after a certain state of atmosphere has prevailed in the spring, the 

 hop, oak, and various other plants, are covered with them in millions. 

 Some have attributed this appearance to spontaneous generation ; others, 

 to the wafting of immense quantities of invisible eggs in the air ; others, to 

 electricity ; some to one thing, some to another ; but I think we may find 

 a solution of this most curious problem in a very striking passage to be 

 found in p. 245. of Huber's book upon ants, and quoted in the Insect 

 Transformations (Library of Entertaining Knowledge}, p. 113. The substance 

 of which is, that in the month of November, while investigating the sub- 

 terraneous chambers of the yellow ant, he found an assemblage of little 

 eggs for the most part of an ebony colour. They were taken the greatest 

 care of by the emmets. In another hill he found a great number of brown 

 eggs, of which the ants took the same care as the former, never abandoning 

 them. Both kinds were totally unlike the eggs of the ant. . " The following 

 day," he says, " I saw one of these eggs open, and an aphis fully formed, 

 having a large trunk, quit it. I knew it to be the puceron of the oak : others 

 were disclosed a few days after, and the greater number in my presence. 

 They set immediately about sucking the juice from some branches of the 

 tree 1 gave them ; and the ants now found within their reach a recompense 

 for their care and attention." The ant-hill was situate at the foot of an 

 oak. " All this," says the Editor of the Insect Transformations, " is done 

 by the ants to secure for themselves a supply of the honey-dew secreted by 

 the aphides in the spring." Here, then, we have the whole mystery of 

 blight explained. The aphis eggs are laid up by the ants and protected 

 during the whiter. As soon as they are born, they hasten away to the 

 neighbouring plant from which the ant had collected the eggs. They begin 

 immediately to lay their eggs; a season more or less favourable arrives, 

 which is indicated by that appearance in the air which is called a blighting 

 wind, and the eggs are hatched in greater or smaller numbers. The new 

 insect immediately begins to lay its eggs, or to produce its living offspring; 

 and as it is calculated that one aphis may be the progenitor (vide Insect 

 Transformations, p. 19.) of 5,904,900,000 descendants during its life, and 

 as there may be twenty generations in a year, it is not to be wondered at 

 that more than 1000 aphides have been counted on a single leaf of the 

 hop, all proceeding from the eggs stored up by the ants for the purpose of 

 securing to themselves a supply of the honey-dew. Should this theory be 

 found to be true, it may by possibility lead to some important practical 

 results, and it is for the purpose of attracting attention to this view of the 

 subject that I address you. We have, then, discovered the store-house of 

 these insects, and whence they come every spring. The question is how 

 to destroy them, or, in other words, how to destroy the ants, their pro- 

 tectors. According to this theory, if we could remove all ants from a hop- 

 garden, or an oak-coppice, we should have no insects in it ; we should have 

 no honey-dew on the leaves ; and most assuredly the plants would be 

 much more healthy and productive. This would be turning the study of 



