OF NATURAL HISTORY. 35 



vlate every difficulty. For this purpofe, he confined, in feparate 

 glafles, the young of fucceffive births, as they dropped from their 

 mothers. Each of thefe, however, were equally fertile, though he 

 continued the experiment to the ninth generation from the original 

 parent *. 



Fads of this kind, which feem to interrupt the ordinary current 

 of Nature, fhould infpire philofophers with caution. They flaould 

 create reverence for fuch of her operations as are already known ; 

 but they ftiould likewife check that lafh fpirit which too frequently 

 draws unlimited conclufions, before the fubjedt be fully inveftigated. 

 Of all induiftions regarding the hiftory of Nature, the neceffity of 

 fexual commerce for multiplying the fpecies appeared to be the mofl: 

 general and the moft legitimate. The oeconomy of the puceron, 

 however, demonftrates, that even this law is not indifpenfable, and 

 that Nature has the power of changing her fteps, and of accomplifh- 

 ing the fame purpofes by various means. 



Having enumerated the different modes by which animals multi- 

 ply their fpecies, I fhall next fhow, that the multiplication of vege- 

 tables is extremely analogous. 



The viviparous, as well as the oviparous animals, are fuppofed to 

 proceed from eggs, with this difference, that the young of the vivi- 

 parous are hatched in the uterus previous to their exclufion. 



Many ftriking analogies fubfifl between the eggs of animals and 

 the feeds of plants. When placed in proper circumftances, they 

 both produce young every way fimilar to the parents. To accora- 

 pli{h this wonderful effed:, the egg requires impregnation and heat. 



E 2 Moifture, 



• Bonnet, Traite d'lnfeftologie, torn. l. p. 74. etfeq. 



