Anomalous Endosperm Development in 

 Maize and the Problem of Bud Sports. 



R. A. Emerson, University of Nebraska. 



(Eingegangen 10. Mai 1914.) 



Anomalous Endosperm. 



Xenia in maize is commonly regarded as an expression of double 

 fertilization. In rare cases xenia appears in only a part, often though 

 by no means usually in approximately one half, of a seed. Thus in a 

 cross between a starchy race and a sugary one or between a colored 

 race and a colorless one, one half of a seed may be starchy and the 

 other half sugary or one half colored and the other half colorless. 



Three hypotheses have been suggested to account for these "half- 

 and-half" seeds. I-Correns (3) and Webber (18) independently sug- 

 gested that the second male nucleus and the fused polar nuclei might 

 develop independently, each giving rise to a part of the endosperm. 

 n-Webber's second hj'pothesis was that the second male nucleus might 

 unite with one of the polar nuclei and that the other polar nucleus 

 might develop independently. Ill -East and Hayes (9) suggested that, 

 following the ordinary union of the second male nucleus with the two 

 polar nuclei, there might occur a vegetative segregation in the endo- 

 sperm, resulting thereby in a sort of bud sport. 



East (8) has compared these hypotheses and has been able to show 

 by means of a novel experiment that hypothesis I (Correns and 

 Webber) is untenable. His evidence was secured from crosses between 

 types of maize with wholly colorless aleurone but which yield colored 

 aleurone on crossing. Colored aleurone is due to the interaction of at 

 least two factors C and R. When an non-colored maize €Crr is crossed 

 with another non-colored maize ccRR, colored aleurone shows as xenia 

 in all the crossed seeds. Six seeds, out of 60000 colored ones produced 



Induktive AbataramungB- und Vererbungslehre. XIV. 16 



