MENDELIAN TERMS 103 



to recognize a " genotype " which includes only such indi- 

 viduals as breed alike, i. e., which produce the same kind or 

 kinds of gametes. A single phenotype often includes two or 

 more categories of genotypes. Thus F2 dominants though 

 all may look alike (be of one phenotype) regularly include 

 both homozygotes and heterozygotes (wholly distinct geno- 

 types). 



