COLOUR-PRODUCING INSECTS. 51 



females. These bear young again, without the 

 concourse of any male insect, and so on for about 

 nine generations. Finally, in autumn, the last 

 generation of females give birth to insects of both 

 sexes. The sexes unite, the males die, and the 

 females deposit eggs upon the branches and die also. 

 These eggs pass the winter season on the spot, and 

 in the spring give birth to females which reproduce 

 similar females, and so on throughout the year 

 without the concourse of the other sex. This is cer- 

 tainly one of the most extraordinary phenomena 

 Natural History has revealed to us. In speaking 

 further on of the genus Melo, I shall refer to 

 similar curiosities in the embryo life of insects, and 

 when speaking of Infusoria, I will make known 

 some extraordinary facts lately discovered, with 

 regard to their development also. 



When Leuwenhoek first announced that the 

 aphides were viviparous, and that he suspected 

 they were born without previous fecundation, the 

 researches of naturalists were immediately directed 

 to this point. Reaumur showed that aphides were, 

 indeed, viviparous ; he then tried to rear them in 

 perfect solitude, but his insects died, and his expe- 

 riment failed. It was reserved for Bonnet to con- 

 firm the ideas of Leuwenhoek. Bonnet reared 

 aphides in complete solitude from the time of their 

 birth, and in a few days remarked that they brought 



