AND THE LOWER ANIMALS. 133 



were of too peculiar a nature, and too inconsistent 

 with accepted views, not to have given rise to many 

 hypotheses. If the aphides always produced their larvgb 

 without sexual intercourse, then the theory of Andro- 

 gynisni would have afforded a sufficient explanation. 

 It would have been easy to suppose the existence in 

 these insects of a double reproductive organ (male and 

 female) in each individual, which could originate new 

 beings in the same manner as those of opposite sexes 

 when distinct. But the alternation of these two modes 

 of generation set this hypothesis aside. 



Bonnet, who was an acknowledged supporter of the 

 "pre-existing germ" doctrine, saw no difficulty in 

 the viviparous production of larvae without previous 

 sexual connection. According to him, the larvse were 

 only germs which were well supplied with nutritious 

 materials by the mother during the summer months, 

 and which on that account were fully developed before 

 leaving the parent. The ova, on the other hand, were 

 germs which had been imperfectly nourished. The 

 action of the male aphis was regarded as an additional 

 means of supplying the ova with nutriment, in order 

 that they might survive the winter and be hatched in 

 spring. 



Eeaumur, who was more observant and less meta- 

 physical than his disciple, was much more puzzled. 

 He put forward several hypotheses without committing 

 himself seriously to any of them. One of these was 

 at all events ingenious. It tended to show that ovi- 

 parous reproduction and its results were in some 

 measure dependent on the arrival of the insect at a 

 state of puberty. He supposed that the adult con- 

 dition was not reached after the individual had lived 



