3793- on varieties of domestic animals. 1ty 
venting an intermixture by copulation. Nor is this 
all: it is also known that if such intermixture be per- 
mitted, the descendants will undoubtedly be a mixed 
breed, evidently participating of the qualities and ap- 
pearences of both its parents. Between'a hound and 
a grehound, a mongrel breed is obtained which pof- 
sefses the sense of smelling, though in a lefs degree 
than the one, and the faculty of fleetnefs in a lefs de- 
. gree than the other, of its parents; and its whole ex- 
ternal appearance evidently indicates at first sight, the 
compound of the stock from whence it has descended. 
‘The same thing is observable in every other mon- 
grel breed: and after the distinctive qualities have 
been thus blended together, it dees not seem’ 
pofsible ever to separate them, so as to obtain once 
more a breed from that progeny, whicli fhall pofsefs 
the original qualities of either of the pareats pure, 
This may be indeed nearly effected, by crofsing re- 
peatedly with @ pure individual, of the unmixed 
breed through many generations ; by which means 
the qualities which were once eguadly blended, will 
become so unequally mixed, as that one of them 
fhall not be discernible ; just a- an equal mixture of 
milk and water might, by frequent additions of pure 
Water, have the miuik so much diluted as to be totally 
imperceptible, 
' Now, im this last case, whether is it more natural 
for me to suppose, when | see the two fluids, milk 
and water, perfectly distinct, that these fluids were o. 
riginally separate and distinctthings, or to believe that — 
both the milk and the water had been the same thing 
sriginally, and by some wonder‘ul procefs, of which 
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