$8* GENERATION. S E CT. XXXIX. 5, 



into organization, as not to produce the organs ne- 

 ceflary to life, as the brain, or heart, or ftomach, 

 that no mule was produced. Where all ihe parts 

 ncceflary to life in thefe compound animals were 

 formed fufficiemly perfect, except the parts of ge- 

 neration, thofe animals were produced which are 

 now called mules. 



The formation of the organs of fexual genera^ 

 lion, in comradiftin6tion to that by lateral buds, in 

 vegetables, and in forne animals, as the polypus, 

 the tasnia, and the volvox, feems the chef d'oeuvre, 

 the matter- piece of nature ; as appears from many 

 flying infers, as in moths and butterflies, who feem 

 to undergo a general change of their forms folely 

 for the purpofe of fexual reproduction, and in all 

 other animals this organ is not complete till the 

 maturity of the creature. Whence it happens that, 

 in the copulation of animals of different fpecies, the 

 parts neceflary to life are frequently completely- 

 formed ; but thofe for the purpofe of generation are 

 defective, as requiring a nicer organization; or more 

 exa& coincidence of the particles of nutriment to 

 the irritabilities or appetencies of the original living 

 filament. Whereas thofe mules, where all the parts 

 could be perfectly formed, may have been produced 

 in earlier periods of time, and may have added to 

 the numbers of our various fpecies of animals, $s 

 before obferved. 



As this production of mules is a conftant effect 

 from the conjun&ion of two different fpecies of ani- 

 mals, thofe between the horfe and the female afs always 

 r^fembling the horfe more than the afs; and thofe, 

 on the contrary, between the male afs and the mare, 

 always refembling the afs more than the mare ; it 

 cannot be afcribed to the imagination, of the male 

 animal which cannot be fuppoicd to operate fo uni- 

 formly ; but to the form of the firft nutritive par- 

 ticles, and to their peculiar flimulus exciting the 



living 



