THE PRANT LOUSE.' 
Genus IX. — /lphis. "The Plant Loufes 
Few infefls are more common than thefe, while few 
prefent greater Angularities to the obfervation of the na~ 
turalift. Plant lice are Ceen on the leaves of a great va- 
riety of plants, and often in fociety, and in conliderable 
numbers. At certain feafons, they are viviparous, and 
at others they produce inanimated eggs, which remain in 
that (late till the action of the fun call forth their vital 
powers. The foitus, when the parent is viviparous, 
{hews figns of life before it is fairly excluded from the 
body. Sometimes the fame mother gives birth to near 
twenty in a day, without appearing lefs in bulk than be- 
fore *. If one of thefe pregnant females are taken and 
prefled between the finger and the thumb, a ft ill greater 
number of young will be forced from her body, one fol- 
lowing another like a ftring of beads, and growing fmal- 
Jer and fmaller, in proportion as their period of natural 
delivery was more remote. 
Reaumur is of opinion that fecundation is performed 
among the females of this tribe, without copulating with 
the malef ; and the experiments of fucceeding naturalills 
have confirmed an aflertion that feems to be contradicted 
by the analogy of all animated nature. Take a plant 
loufe, the inftant it iffues from its mother ; flrnt it up 
earefuliy from all accel's to congenerous animals ; and if 
k 
* Reaumur, Tom. IH. p. 191. 
f Memoir, pour fervir a L’Hift de» Infti 5 les,Tom, III. mem. fi. 
