142 EXAMINATION OF 



into a chryfalis, before it arrives at the perfect 

 ftate of a flie, and before it acquires the power 

 of generating. But the fpermatic worm has no 

 generative faculty ; neither does it proceed from 

 an egg : And, though it fhould be fuppofed that 

 the femen contains eggs which produce the fper- 

 matic animals, the fame difficulty ftill remains ; 

 for thefe fuppofed eggs are not a refult of the 

 copulation of two fexes, like thofe of infeds. Con- 

 fequently, the analogy fails here likewife ; and 

 the transformation of infeds, in place of ftrength- 

 ening this hypothefis, feems to deftroy it en- 

 tirely. 



The feeds of vegetables are reforted to, in or- 

 der to account for the infinite number of fper- 

 matic animals : But this analogy does not ap- 

 ply; for all the fpermatic animals, one only ex- 

 cepted, muft abfolutely perifli. The feeds of 

 vegetables, however, are not fubjed to the fame 

 neceffity. When they become not vegetables 

 themfelves, they nouriih other organized bodies, 

 and ferve the purpofes of growth and of repro- 

 dudion to animals. But the prodigious fuper- 

 fluity of fpermatic animals can anfwer no end 

 whatever. I make this remark, purely becaufe 

 I wifh to omit nothing that has been advanced 

 on the fubjed ; for I acknowledge, that no ar- 

 gument drawn from final caufes can either e- 

 Ilablifli or deftroy a phyfical theory. 



The apparent equality in the number of fper- 

 ir^atic animalcules in all animals, has alfo been 



objeded 



