SEP 2 1916 



The American Botanist 



VOL. XXII 



JOLIET, ILL., MAY, 1916 



No. 2 



^mid the thousand blossoms of the l/me 

 ZJhe ffossi'p bees £fo hurri/in^ to and froj 



^nd oh, the busy yoy of wor/ciny time, 



J^nd oh, the fragrance where the lime trees yrow. 



— Augusta Webster. 



XENIA IN MAIZE 



By Adolph E. Waller. 



^ I 'HE formation of the endosperm of a great many seeds 

 from a triple fusion is a well known fact to all students 

 of botany. When the contents of a pollen grain are discharged 

 through the pollen tube, the first sperm fuses with the egg to 

 form the embryo, while the second sperm unites with the two 

 polar bodies, or polar nuclei, to form the definitive nucleus. 

 This later becomes the endosperm tissue surrounding and pro- 

 tecting the embryo. It is here that a reserve supply of starchy 

 material is stored. After the seed is planted and sprouting 

 starts, the embryo draws on the endosperm for its food supply 

 until the young plantlet can nourish itself. 



The phenomenon called xenia is intimately connected with 

 triple fusion. Xenia shows the immediate influence of the pol- 

 len in subsequent endosperm formation. If the second sperm 

 from the pollen brings with it determiners for a dominant char- 

 acter that expresses itself in the endosperm, i. e. if pollen from 

 blue flint corn is transferred to the silks of white dent corn, then 



