1793. on varieties of domestic animals. 237 
ticular breed which pofsefses in the most eminent de- 
gree the qualities he wants, opens up to the atten+ 
tive econome a wide range for observation and expe- 
riment. 
But if all this were done, his progrefs does not 
stop here. He may find, after he has examined them 
all, that certain peculiarities which might be useful 
to him, are not to be found in the highest degree pof- 
sible in any one of these. He may observe that if 
the carcase of one were mended in’ certain respects, 
by being blended with that of another, it would be 
better than either; and so of fleece, hardinefs &c. &c: 
so that by crofsing one breed with another, a mong- 
rel kind might be produced, that would be more be- 
neficial to him than that of either of the parents. 
Thus may he mix and compound them as it were at 
pleasure ; and in this way he may produce another 
diversity of breeds, that nature never would have 
produced without his intervention, 
Thus does it appear that animals, if left to breed 
by themselves in a wild state, would naturally pre- 
serve the varieties distinct and separate from éach o- 
ther, so as seldom if ever to produce any new va- 
rieties, and that of course if there had been originally 
but one only of each species, the probability is that 
that one kind would never have deviated into a great 
mite. Here therefore I with to put philosophical subtleties, which © 
may have a tendency on some occasions to confound the understand- 
ing, entirely out of the question, and refer to plain matters of fact. A- 
pout po/sibilities, our limited knowledge forbidsus*to pronounce; here 
a probability, which may be as ten thousand to one, is, for every 
practical purpose, to be considered as a certainty. 
