234 HEREDITY AND ENVIRONMENT 



which become latent in the process, recessive/' 

 These hybrids 1 when self-fertilized gave rise 

 to a second filial generation of individuals 

 some of which showed the dominant character 

 and others the recessive, the relative numbers 

 of the two being approximately three to one. 

 Thus the hybrids produced by crossing yellow- 

 seeded and green-seeded peas yielded when 

 self-fertilized 6,022 yellow seeds and 2,001 

 green seeds, or very nearly three yellow to 

 one green (Fig. 48). The hybrids produced 

 by crossing round and wrinkled seeded varie- 

 ties yielded in the second filial generation 5,474 

 round and 1,850 wrinkled seeds, or approxi- 

 mately three round to one wrinkled (Fig. 

 52) . The hybrids from tall-stemmed and short- 

 stemmed parents produced in the second filial 

 generation 787 long-stemmed and 277 short- 

 stemmed plants, or again approximately three 



1 Bateson introduced the term "homozygote" for pure-bred 

 individuals resulting from the union of gametes which are 

 hereditarily similar, and "heterozygote" for hybrids resulting 

 from the union of hereditarily dissimilar gametes. The 

 gametes formed from a homozygote are all of the same 

 hereditary type, those formed from a heterozygote are of two 

 different types for every unit difference of the parents. 



