x		--»
P1		P2		F1
Yellow		green		all Yellow
	x		--»
F1		F1
				F2
(F2) Yellow : green = 3 : 1
If there are discrete heredity units
in pairs, than not all F2 yellow
coloured seeds are the same as
those from the parental
generation. Some will be -having
the dominant unit for producing the
characteristic yellow twice than-,
but others will be as the yellow
seeds in the F1 generation which
have the dominant yellow
producing unit and the recessive
green one latent present.
If this thesis is correct, than again
it can be demonstrated by the ratio
between the quantities of yellow
and green seeds to be found in the
offspring of backcrosses of the F1
and F2 yellow seeds with the green
seeds of the parental generation.
For these green seeds have double
recessive heredity units producing
the green characteristic so that, if
the green colour producing
heredity unit is latent in those F1
and F2 yellow seeds, green seeds
will and must be found in the
offspring of these crosses in
quantities corresponding to the
number of possibilities for passing
on these discrete heredity units.
So Mendel executed hundreds of
these back crosses and indeed
				1/2 yellow
	x		--»
F1		P2
				1/2 green
-------------------------------------------
				2/3 yellow
	x		--»
F2		P2
				1/3 green
the foreseen ratio were found.