318 Belliug. 



50 per cent become full of cj-toplasm. The microspores of the 

 hybrids segregate into viable and nou-viable, in the simple 

 ratio, for the haploid generation, of 1 : 1. 



Ovules of the hybrids (Fi). 

 Velvet by Lyon. — The dry pods of the 7 hybrid plants commonly 

 showed one or more constrictions where ovules had aborted.' jThere 

 were few pods with as many as 5 or 6 ripe seeds. In this the hybrids 

 differed conspicuously from their parents. One raceme, taken at random, 

 was counted. It bore 9 pods, which contained 26 seeds and 26 aborted 



Fig. 10. Selected poil iif the first generaticm of the Lyon by Velvet cross. 

 Natui'al size. 



ovules (undei' one niilliiiieter in diameter), giving .50 for the percentage 

 of ovules aborted. 



Lyon by Velvet. — The pods of the 6 hybrid plants (Fig. 10) 

 resembled those of the reciprocal cross. One raceme, taken at random, 

 was counted. There were 1.3 pods, with 48 seeds and .32 aborted 

 ovules; thus 40 per cent of the ovules were aborted. 



Velvet by Yokohama. — The pods of the 11 hybrid plants (Fig. 11) 

 resembled those of the above crosses. Thc^ aborted ovules were counted 

 in one plant, and in a laiidom part of the crop of another plant. 



T, ,• -vT T-> 1 CI Aborted Percentage of 



Pedigree No. Pods Seeds , , , , 



ovules ovules aborted 



V^' 7 306 1022 857 46 



V^' 4 (part) 92 308 255 45 



