116 University of California Publicafions in Botany I ^ol. 5 



The question of Xenia and the double fertilization in the 

 seed of maize (East and Hayes, p. 101, and the literature there 

 cited), is the only matter which bears directly on the above 

 explanation. The discussion given by Bateson (1909, p. 270), is 

 interesting in this connection, yet we seem to have some experi- 

 mental evidence which goes to show that the two nuclei brought 

 into the embryo sac by the pollen tube do not bear similar or 

 even corollated allelomorphs and that all the nuclei of the embryo 

 sac are not similar in composition. The above explanation, in 

 general, seems possible from a cytological point of view (Coulter, 

 Barnes and Cowles, 1910, p. 269), and is as theoretically con- 

 ceivable as certain other methods of interpretation which have 

 recently been put forward. 



