332 



Belling. 



those with half-aborted polleu have half their ovules aborted. Tliis was 

 confirmed by sections of ovaries from one plant ■\\ith fertile pollen 

 and from one plant with half-aborted pollen taken at random from the 

 second generation of Velvet by Yokohama. 



To sum up: — In the second generation half the plants 

 have sound pollen-grains and good ovules, and the other half 

 of the plants have half their pollen-grains and half their 

 embryo-sacs aborted. We may neglect the diploid generation almost 

 altogether, and say that a haploid generation, half of whose members 

 abort, gives, after conjugation, equal numbers of normal haploid families 

 and half-aborted haploid families. 



Fertility of the Third Generation. 



Pollen of the Third Generation. 



Velvet by Lyon. — This generation was grown on a large scale 

 in competition with sorghum, and the pollen was not examined. 



Lyon by Velvet. — Twenty-one families were grown in 1913. 

 Most of these had undergone a stringent selection for pod-pubescence, 

 earliness, size of crop, etc.; but three black plants and one plant with 

 stinging hairs were grown. The following list gives the second generation 

 parents, according as they had fertile or half-aborted ovules. 



