32 HISTORY AND PHYSIOLOGY. 



to the aphis, Bonnet says the influence of the male 

 continues through Jive generations, but Lyonnet 

 carried his experiments to a more extended pe- 

 riod ; and according to Messrs, Kirby and Spence, 

 who give it " upon the authority of Mr. Wol- 

 nough of Hollesley (late of Boyton) in Suffolk, an 

 intelligent agriculturist, and a most acute and ac- 

 curate observer of nature, there may be twenty 

 generations in a year." Reaumur has proved that 

 in Jive generations one aphis may be the progeni- 

 tor of 5,904,900,000 descendants. It may be ob- 

 jected to me here, that the aphis is a viviparous 

 insect, and that the experiments which prove what 

 I have referred to, do not therefore bear upon 

 the question. It has been ascertained, however, 

 that they are strictly oviparous at the close of the 

 year (one species is at all times so), at other times 

 ovo-viviparous ; and in either case the penetra- 

 ting influence of the male sperm is surely still more 

 remarkable where there has been no immediate 

 commerce with the male, than in the direct case 

 of the oviparous bee ! It has been observed, how- 

 ever, that the further the female aphides are re- 

 moved from the first mother, or that which had 

 known the male, the less prolific do they become. 

 In order to put my readers in possession of Dr* 

 Fleming's opinion upon this subject, I will quote 

 what he has said in his Philosophy of Zoology. 

 " Impregnation, in insects, appears to take place 



