THE DETERMINATION OF SEX 



217 



Doncaster and Raynor, in 1908, published the results 

 of various crosses between these two varieties which 

 demonstrate clearly that sex is a Mendelian character 

 and that, in this instance, maleness is homozygous 

 and femaleness heterozygous with the determiner 



Key to Symbols 



Phenotype 



Gross.c? 



Gross, c? 



Lact.c? 



GR0SS.9 



Lact.^ 



Conslilulion with 

 respect to ihe 



GROSSULARIATA 



factor 



Dupl ex 



Simplex 



fSlulliplex 



Simplex 



Nulliplex 



Genotype 



(joi Ooi 



Iqi Ooi 



()0I Jfll 



Oof flo 



Ooi Do 



Gametes 



01 



Fig. 67. — Key to the symbols employed in Figures 68-71. The outline 

 symbols represent samples of the autosomes or somatic chromosomes. 

 The black symbols stand for the "extra" or sex chromosomes. G 

 above a black symbol indicates the grossulariata factor linked with a 

 sex chromosome. The variety lacticolor occurs whenever the grossu- 

 lariata factor is absent. 



for maleness linked with the factor producing the 

 variety grossulariata. A study of Figures 67-71 

 will make this case clear. Outline symbols represent 

 ordinary chromosomes or autosomes, several of which 

 are omitted for sake of clearness. The black sym- 

 bols represent sex chromosomes. The letter G placed 



