124 THE INSECT WOELD. 



look upon it as a female. From that day up to the 20th, inclu- 

 sive, she produced ninety-five little ones, all alive and doing 

 well, the greatest number of which were born under my own 

 eyes!"* 



He very soon made some other experiments on the aphis of the 

 elder-tree, so as to assure himself if the generations of plant-lice, 

 reared successively in solitude, preserved the same property of 

 procreating without copulation. 



" On the 12th of July," says he, " about three o'clock in 

 the afternoon, I shut up a plant-louse that had just been born 

 under my eyes. On the 20th of the same month, at six o'clock 

 in the morning, it had already produced three little ones. But I 

 waited till the 22nd towards noon, before I shut up a plant-louse 

 of the second generation, because I could not manage earlier to be 

 present at the birth of one of those produced by the mother I had 

 condemned to live in solitude. I always continued to observe the 

 same precaution. I shut up only those plant-lice which were born 

 under my very eyes. A third generation began on the 1st of 

 August ; it was on this day that the plant-louse I had shut up 

 on the 22nd of July gave birth to this generation. On the 4th of 

 August, about one o'clock in the afternoon, I put into solitary 

 confinement a plant-louse of the third generation. On the 9th of 

 the same month, at six in the evening, a fourth generation, due 

 to this last one, had already seen the light : it had given birth 

 to four little ones. On the same day, towards midnight, all com- 

 merce with its own species was forbidden to the plant-louse of the 

 fourth generation, born at that hour. On the 18th, between six 

 and seven o'clock in the morning, I found this last in the company 

 of four little ones, to which it had given birth. "f 



In this case, the want of food caused the death of the isolated 

 individual of the fifth generation, and the experiment was brought 

 to a close. 



Bonnet then tried experiments on the plantain aphis, following 

 them up during five consecutive generations, which succeeded each 

 other without interruption, in the space of three months. 



* Traite d'Insectologie, ou Observations sur les Pucerons ;" Ire partie, ISmo, 

 Paris, 1745, pp. 2838. 

 f Ibid. pp. 6769. 



