84 THE BOTANICAL MAGAZINE. [Voi. xxx. n.,. ;i5i. 



life, and serving the definitive embryo as a nutrient tissue for 

 its development. 



In the light of this fact of ontogeny it is most reasonable 

 to consider any character belonging to the endosperm of maize- 

 seed as caused by the two-fold presence of all character-units 

 of the maternal plant and the single presence of all character 

 units of the paternal or the pollen plant. 



The essential process about the formation of angiospermic 

 endosperm is described in chief handbooks of the science of 

 heredity, on the occasion of the explanation of the phenomenon 

 called xenia by Focke. 



Still, so far as we are aware, this cytologically well estab- 

 lished fact has not been accounted for in the construction of 

 the heredity-formula for zygotes in the works of the Mendelian 

 principle. Owing to this fact, the actual results of crossing of 

 two different strains of maize are sometimes apparently ab- 

 normal, and widely differ from theoretical distinctions of 

 various zygotes. 



As is well known to breeders of maize, intensity of black or 

 blue colour of the seeds of i*\-cob differs remarkably in two 

 cases of reciprocal crossings of a certain black or blue strain 

 with a certain white strain. When a black strain is used as 

 the maternal plant, the seed colour produced is much darker 

 than in the case when the white strain was used as the ma- 

 ternal plant. Thus api)arenth' the inheritance is considerabl3'^ 

 dominating on the maternal side. This remarkable fact is 

 nothing but what it should be after the new formula here 

 proposed of Frzygote, while it is inexplicable by the formula 

 formerly used : 



P. P. 



A, gametic formula of the a, gametic formula of the 

 dark blue (apparently white strain, 



black) strain. 



I. AA.a, Z3'gotic formula when the plant with the gametic 



formula A was taken as the m^iternal plant. 



II. na.A, zygotic formula when the ])lant with the gametic 



formula a was taken as the maternal plant. 



