Variation and Heredity 281 
together, there are produced two kinds of individuals, A’s 
and £’s, of which there are three times as many A’s as B’s. 
It has been found, however, that some of these A’s are pure 
forms, as indicated by the A on the left in our table, while 
the others, as shown by their subsequent history, are hybrids, 
A(B). There are also twice as many of these A(B)’s as of 
the pure 4’s (or of the 4’s), Thus the results are really the 
same as in our imaginary case, only obscured by the fact that 
the A’s and the A(4)’s are exactly alike to us in respect to 
the character chosen. We see also why there appear to be 
three times as many A’s as B’s. In reality the results are 
1 A, 2 A(B), 1 B. 
In subsequent generations the results are the same as in 
this one, the A’s giving rise only to A, the B’s to B, and the 
A(B)’s continuing to split up into the three forms, as shown in 
our diagram. , Mendel found the same law to hold for all the 
characters he examined, including such different ones as the 
form of the seed, color of seed-albumen, coloring of seed-coat, 
form of the ripe pods, position of flowers, and length of stem. 
Mendel also carried out a series of experiments in which 
several differentiating characters are associated. In the first 
experiment the parental plants (varieties) differed in the form 
of the seed and in the color of the albumen. The two char- 
acters of the seed plant are designated by the capital letters 
A and &; and of the ‘pollen plant by small a@and 4. The 
hybrids will be, of course, combinations of these, although 
only certain characters may dominate. Thus in the experi- 
ments, the parents are AB (seed plant) and aé (pollen plant), 
with the following seed characters : — 
Seed parent $ A form round Pollen parent § a form angular 
AB B albumen yellow ab b albumen green 
When these two forms were crossed the seeds appeared round 
and yellow like those of the parent, AB, z.e. these two char- 
acters dominated in the hybrid. 
