ASS. 
IHIS well-known useful but neglected qua- 
druped, from it's great resemblance to the 
horse, might naturally be supposed of the same 
species, only somewhat degenerated from that 
noble animal: the species, however, are per- 
fe6lly disiindl, and there is an inseparable line 
drawn between them, the animal produced from 
the mixture of ahorse and an ass being barren. 
This, indeed, seems to be the barrier between 
every species of animals, which keeps them 
asunder, and preserves the unities of their 
forms. If the mule, or monster, bred be- 
tween two animals whose forms nearly ap- 
proach each other, be no longer fertile ; we 
may conclude that the animals, whatever ex- 
ternal similitude appears between tliem, are 
distin6b and separate kinds. Nature, who always 
provides for the pcrfe6lion and preservation 
of her productions, has wisely stopped the 
fecundity of these ill-formed produclions, to 
preserve the form of every animal uncontami- 
aated : were not this the case, the different 
species 
