INDEPENDENT MENDELIAN INHERITANCE 91 
The F, hydrid ZzRrli was the normal flower form and produced 
blossoms of a magenta coloration, 7.e., red on ivory. From self-fertilized 
seed of such plants there were produced 124 plants distributed with 
respect to their phenotypes as shown in Table XIII. Forso smalla popu- 
lation, in number of individuals only about twice that necessary to obtain 
a triple recessive, the agreement is good. 
To account for these hybrid results on a chromosome basis it is 
necessary to assume merely that the three pairs of allelomorphs are borne 
in different pairs of chromosomes. When germ cells are formed in the F; 
See. 
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Fic. 45.—Diagrammatic representation of reduction divisions in an F, snapdragon of the 
genetic constitution ZzRrIt. 
- hybrids the members of the three pairs of chromosomes separate independ- 
ently so that eight different kinds of gametes are formed. In Fig. 45 are 
shown diagrammatically the reduction divisions in an F’; snapdragon of 
the genetic constitution ZzRrIi. Since any one of these types of re- 
duction has a good as chance of occurrence as any other one, the eight 
kinds of gametes are produced in substantially equal numbers. When 
such a plant is self-fertilized there are 64 possible combinations as shown 
in the checkerboard in Fig. 46. In the description of phenotypes in this 
checkerboard certain differences between homozygous and heterozygous 
forms have been disregarded. This is true particularly for the Kr 
individuals as contrasted with the homozygous RR individuals. The 
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