INHERITANCE OF A MACULA MUTATION. 



271 



TABLE VI. 



BACK CROSS TEST. 



Pi: Heterozygous, Mm, spotted female X homozygous, MM, spotted male. 

 Fi: Offspring: 



heterozygous spotted (Mm) males. The offspring from 15 pairs, 

 gave 236 spotted (MM, Mm) females and 213 spotted (MM, Mm) 

 males. Hence, both sexes were homozygous for the macula 

 (MM) genes, and heterozygous for the macula (M) gene and 

 normal (m) factor. The macula mutation is dominant to the 

 wild type. Complete data is presented in Table VII. 



TABLE VII. 



BACK CROSS TEST. 

 Reciprocal Cross. 



Pi: Homozygous, MM, spotted female X heterozygous, Mm, spotted male. 

 Fi: Offspring: 



