1793- on varieties of domestic animals. 11g 
man I believe ever had a white pea from a gray, Or 
a gray froma white. If white pease perfectly un- 
mixed with gray are sown, it is well known the 
whole of the produce will be white, and so of gray : 
many plants also belong to this clafs. 
A third clafs, like that of animals, may be raised 
by seeds either pure and unadulterated, or mixed and 
of a mongrel breed, at pleasure. Cabbages afford a 
noted instance of this sort: white or red cabbages 
may be reared from seeds without degenerating, for 
any length of time, if the two kinds be kept at a 
great distance from each other; but fhould a white 
cabbage be allowed to perfect its seeds in the neigh- 
bourhood of red cabbages producing seeds at the 
same time, a mongrel kind would rise from these 
seeds, which would not be pure white, nor distinct 
red, but a pale red compounded of the two. Early 
and late cabbages; which are very distinguifhable 
from each other in several respects, besiies earlinefs, 
are adulterated in the same manner. Savoys in like 
manner may be blended thus also with cabbages or 
other greens. In fhort, the peculiarities affecting this 
clafs of plants, are precisely similar to those affecting 
different breeds of dogs, and other animals ; so that 
when once a mongrel breed has been obtained, there 
-is no recovering the true sort, but by a frefh impor- 
tation of uncontaminated seeds, though the mongrel 
sort may be preserved as long as you please by pro~ 
pagating it by itself. 
The inference I would draw from these facts, (and 
other clafses of plants might be named) is, that 
since we find naturalists have overlooked some very 
