270 THE SCHOOL OF REAUMUR 



had started, and which had attracted the notice of 

 several other naturalists during the forty years' interval 

 between the Gontinuatio Arcanorum and the Histoire 

 des Pucerons. He showed that both the winged and 

 the wingless aphids may be viviparous ; Leeuwenhoek 

 had concluded too hastily that the wingless forms are 

 immature insects, destined afterwards to acquire wings. 

 Reaumur was aware that the unfertilised females can 

 bear young, and he endeavoured to rear successive 

 generations of viviparous aphids, but was accidentally 

 hindered. Leeuwenhoek had concluded from his own 

 observations that ants devour aphids, and are the great 

 natural check upon their inordinate increase ; Reaumur, 

 however, confirmed and corrected the view which Goedart 

 had put forth long before and which Frisch had defended ; 

 he showed that when ants seek out aphids, it is not 

 usually in order to prey upon them, but to drink their 

 sugary exudation. He found small red ants, probably 

 Formica rufa, dwelling underground in company with 

 grey aphids. All honeydew, E^aumur maintained, is 

 the product of aphids, a statement which has been con- 

 firmed by later observers. He showed that a fluid is 

 exuded from the tubes which in most aphids stand up 

 from the hinder part of the abdomen, but he could give 

 no account of the use of the fluid.^ 



Reaumur's Aphis-studies enabled him to suggest to 

 his young friend, Charles Bonnet, the inquiry which 

 has immortalised his name, and in the last volume of 

 the Histoire des Insectes ^ Reaumur had the satisfaction 

 of noticing Bonnet's discoveries with warm praise. 



'Bonnet {Traiti d'Insectologie) was the first to observe that aphids defend 

 themselves by directing the extremity of the abdomen (which bears the 

 tubules) towards an enemy. 



2 Vol. VI, pp. 523-568. 



