ijg EXAMINATION OF 



As phyficians are at prefent divided between 

 the fyftem of fpermatlc worms, and that of eggs, 

 and as every new writer upon generation ha^ 

 adopted either the one or the other of thefe hy- 

 pothecs, it is neceffary to examine them with care, 

 and to fhow not only their infufficiency to ex- 

 plain the phaenomena of generation, but that 

 they reft upon fuppofitions which are entirely 

 deftltute of probability. 



Both fyftems fuppofe an infinite progrefTion, 

 which, as formerly remarked, is a mere illufioA 

 of the brain. A fpermatic worn! is more than 

 a thoufand million of times fmaller than a man. 

 If, then, the body of a man be taken as an unit, 

 the body of a fpermatic worm will be expreffed 

 by the fraaion -----\----, i. e, by a number 

 confifting of ten cyphers ; and, as man is to a 

 fpermatic worm of the firft generation in the 

 fame proportion as this worm is to a worm of 

 the fecond generation, the fize of this laft fper- 

 matic worm will be expreffed by a number con- 

 fifting of 19 cyphers ; for the fame reafon, the 

 iize of a fpermatic worm of the third generation 

 muft be exprefled by a numbef confifting of 28 

 cyphers, that of the fourth generation by 37 

 cyphers, that of the fifth generation by 46 cy- 

 phers, and that of the fixth generation by 55 

 cyphers. To form an idea of the minutenefs 

 reprefented by this fradlion, let us take the dl- 

 menfions of the fphere of the univerfe from the 

 Sun to Saturn ; and, fuppofing the Sun to be a 



miUion 



