PAIRING OF APHIDES. 235 



ducted in the most rigid scientific manner — Nature, 

 as is well remarked by Bonnet, having sown them 

 upon all sorts of plants and trees, to provide food 

 for other species of insects, as we sow grain for our 

 own subsistence.* In a word, it appears that the 

 old opinion maintained by Leeuwenhoeck, Cestoni, 

 and Bourguet, which maintains aphides to be gene- 

 rated without pairing, is partially true. Reaumur, in 

 consequence of repeated accidents, was unsuccessful 

 in his observations ; but Bonnet, by extraordinary 

 patience and care, succeeded beyond what could 

 have been anticipated. We think his experiments 

 cannot fail to prove interesting. 



Upon a leafy branch of spindle-tree [Etiomjmus), 

 plunged in a phial of water, and set in a garden-pot, 

 he placed an aphis which he had seen born the in- 

 stant before of a mother without wings ; and having 

 previously examined the leaves and stem with the 

 most miimte care lest there might be any other 

 aphides upon them, he covered the whole with a 

 glass vessel, the edges of which being plunged into 

 the mould, he felt as confident that he had the 

 control of the conduct of his prisoner as Acrisius 

 did as to the actions of Danae when he shut her 

 up in a brazen tower. This was done on the 

 20th of May at five in the evening ; and he con- 

 tinued to watch with a magnifying glass the im- 

 prisoned insect every day from hour to hour, begin- 

 ning about five in the morning, and leaving off about 

 nine or ten at night, noting its every movement in his 

 journal. It changed its skin four times, in the same 

 manner as caterpillars, and during the last moult 

 it caused our ingenious experimenter not a little un- 

 easiness, from its appearing as if it were preyed upon 

 by internal parasites,| as in that case he would have 



* Insectologie, GEuvres, i, 10. 



t See Insect Transformations, page 57, &c. 



