HEMIPTEEA. 123 



by his experiments on the reproduction of plant-lice. This 

 naturalist, whose name will live quite as long as those of 

 Reaumur and of Tremblay, was Charles Bonnet, of Geneva. 



Charles Bonnet made the extraordinary discovery that aphides 

 can increase and multiply without copulation. An isolated speci- 

 men can produce a series of generations of its kind. We will 

 relate the curious experiments of the Genevese naturalist. He 

 placed in a flower-pot, filled with mould, a phial full of water, and 

 put into this phial a little branch of spindle, having only five or 

 six leaves, and perfectly free from any insect. On one of these 

 leaves he placed a plant-louse, which was born under his own eyes, 

 of a wingless mother. He then covered the branch with a glass 

 shade, whose rim fitted exactly into the top of the flower-pot. 

 Having taken these precautions, Charles Bonnet was perfectly cer- 

 tain of being able to observe his prisoner at his ease. He could 

 keep it under his eye and under his hand, with more certitude and 

 security than was the mythological Danae, shut up, by order of 

 Acrisius, in a tower of bronze. 



" I took care," says Charles Bonnet, " to keep a correct journal 

 of the life of my insect. I noted down its least movements ; 

 nothing it did seemed to me indifferent. Not only did I observe 

 it every day from hour to hour, beginning generally at four or 

 five o'clock in this morning, and only leaving off at about nine 

 or ten at night ; but I even looked many times in the same hour, 

 and always with the magnifying glass, to render my observation 

 more exact, and to learn the most secret actions of my little lonely 

 one. But if this continual application cost me some trouble, and 

 bored me not a little, in amends I had some cause for self-applause 



and for having subjected myself to all this trouble My 



plant-louse changed its skin four times, on the 23rd, in the 

 evening ; on the 26th at two in the afternoon ; on the 29th at 

 seven o'clock in the morning; and on the 31st at about seven 



o'clock in the evening Happily delivered from these four 



illnesses through which it was obliged to pass, it at last reached 

 that point to which, by my care, I had been trying to bring it. 

 It had become a perfect plant-louse. On the 1st of June, at about 

 seven o'clock in the evening, I saw, with great satisfaction, that it 

 had given birth to another ; from that time I thought I ought to 



