110 



Mary Gordon.- 



it is possible that the number of centres is the same in all of 

 the groups and only show up clearly when starch is deposited in 

 them. 



Occasionally nuclei are to be found dividing in the endosperm 

 two or three cells below the actively dividing surface layer 

 (Text Fig. rV.). This is not inconsistent with the idea of a 

 cambium, as cells formed from a cambium frequently divide 



Text Figure IV. 



Transverse section of young oat grain showing nuclei of first and second 

 layers in mitosis. 



again. In the endosperm of barley binucleate cells sometimes 

 occur (Text Fig. V.), and it is possible that after the original 

 nucleus divided the two daughter-nuclei lie close together in the 

 cell, and are prevented from separating by the presence of 

 starch which soon becomes deposited in the cell. This also 

 would prevent the formation of a new cell wall, thus giving a 

 single binucleate cell. 



