THE GERM-PLASM THEORY 303 
and one-fourth green. This proved that the seeds 
of the first generation (F;), although yellow, still 
possessed within them the factor for greenness in a 
latent condition. Green was therefore called a re- 
PARENTS 
GAMETES 
Eces 
ow 
on 
Fe OQ QO 
Fs 
Fig. 81.— Diagram to illustrate Mendel's law of segregation. Individ- 
uals (zygotes) are represented by superimposed circles, whose colors 
stand for the factors involved. Gamctes (germ cells) are represented 
by single circles. (From Morgan, 1914.) 
cessive character and yellow a dominant character. 
As a result of breeding the (F:) second generation it 
was found that all of the green seeds produced plants 
which bore green seeds; that is, these plants were 
pure green and “homozygous” as regards color; 
whereas the plants which bore yellow seeds could be 
