lo ANALOGIES BETWEEN 



Befide being more #rongly charaderlfed, e- 

 very ipecies of animal is diftinguifli.ible from 

 another by copulation. Thofe may be regarded 

 as of the fame fpecies which, by copulation, u- 

 niformly produce and perpetuate beings every 

 way fimilar to their parents ; and thofe which, 

 by the fame means, either produce nothing, or 

 diffimilar beings, may be confidered as of diife- 

 rent fpecies. A fox, for example, will be of a 

 different fpecies from a dog, if nothing refults 

 from the intercourfe of a male and a female of 

 thefe two animals ; or, if the relukbe a diiliinilar 

 creature, a kind of mule, as this mule cannot 

 multiply, it will be a fufficient demonllratioii 

 that the fox and dog are different fpecies of ani- 

 mals. In plants, we have not the lame advan- 

 tage ; for, though fexes have been attributed to 

 them, and generic diftindlionshave been found- 

 ed on the parts of frudificalion; yet, as thefe 

 charadteriflics are neither fo certain nor fo ap- 

 parent as in animals ; and, as the reproduvftioii 

 of plants can be accomplifhed by feveral me- 

 thods whicli have no dependence on fexes, or 

 the parts of frudification, this opinion has not 

 been uaiverfally received ; and it is only by the 

 mifapplication of analogy, that thefexual fyiteni 

 has been pretended to be fufticient to enable us 

 to diftinguiih the diiTerent fpecies of the vege- 

 table kingdom. 



Though the fpeciesof animals be more nume- 

 rous than thofe of plants, the number of indi- 

 viduals 



