AND THE LOWER ANIMALS. 129 



almost invariably motionless, and having their long 

 proboscis deeply buried in the epidermis of the plant, 

 they appear capable of only one movement, — that of 

 raising from time to time the great round abdomen 

 which is terminated by two small tubes in the form 

 of moveable horns. Each time they move, a drop of 

 sugary liquid escapes from these openings, and in the 

 neighbourhood may usually be seen a few ants, ready 

 to suck up the honeyed secretion, which according to 

 Hubert, — the distinguished observer of these insects, 

 — is probably their sole nourishment. These larvae, 

 when completely developed, become pretty insects, 

 with four transparent wings almost twice as long and 

 as wide as the entire body, and which are supported 

 by a few thin nervures. So far there is very little 

 extraordinary in the history of these hemiptera. 



The larva3 alone were at first examined by Leu- 

 wenhoek, La Hire, and Reaumur. The latter, whose 

 attention was absorbed by other researches, after- 

 wards engaged Ch. Bonnet to investigate the subject, 

 and the Swiss naturalist fully justified the confidence 

 reposed in him by his illustrious master. 



It was already known that the plant-bugs produced 

 two generations, and it was suspected that each 

 individual possessed the two sexual attributes. To 

 ascertain the truth of this suspicion, Bonnet isolated 

 one of these insects almost immediately after its 

 birth, and reared it in captivity, taking the greatest 

 precautions to prevent any intercourse with other indi- 

 viduals. This nurseling was treated by our observer 

 with an amount of care which he has naively described 

 in his work.* He watched it with a lens, from 



* "Traite d'lnsectologie," 1745. 

 K 



