TfiE PLANT LOUSE, 437 



it prove a female, it will produce young : In like man- 

 ner, the young produced from this virgin loufe, kept fe- 

 parately, will produce an ofFspring. Some naturalifts 

 have repeated this experiment to the third and fourth re- 

 produ£lion. Bonnet obferved nine fuccefilve generations 

 of this nature, all in the fpace of three months. The moll 

 probable account of this lingular facl feems to be this ; 

 that as in all animals fecundation is accompliflied by the 

 copulation of male and female ; fo that happens with the 

 plant lice ; but with this difference, that the fecundation 

 produced by that acb is tranfmitted for feveral genera- 

 tions, before the prolific virtue becomes entirely ex- 

 haufled. 



The young, immediately after being protruded from 

 the inother, are always of a paler colour than the parent: 

 They have then the entire ufe of their limbs, and go iii 

 quell of food. All the diiferent kinds call their Ikin ; 

 and it is after th^fe developeraents that fuch of them as 

 have wings obtain thefe parts. 



It is not the males only that are winged, as we have 

 feen in fome other genera; many of the plant lice of 

 both fexes are deprived of thefe inllruments in their moll 

 perfe£l ilate ; for many of the females without them are 

 lieen producing young. As the larvae of thefe infects 

 polTffs all the aftivity peculiar to their genus in its lall 

 ftage of growth, fo they are equally diflinguiihed by vo- 

 racity. They are furniflied with a fmall trunk, which 

 pierces the leaves, and enables the animal to extrafl the 

 juices proper for its nourilhmcnt. Many plants grow 

 deformed by the number of punctures thus made upon 

 their leaves, and decay from the want of their ufual fap. 

 Some thrive even when covered with thefe infeiSls , while 

 ©thers rife up into fmall hollow tubercles, which, on 



being 



