The Mode of Inheritance of Semi-Sterilit}- in the Offspring of Certain Hybriii Plants. 309 



■biometrical investigation. The egg parents of the cross of Velvet by 

 Yokohama in 1911 belonged to the line of Velvet beans pedigreed since 

 1908. The pollen parents belonged to a farm crop of Yokohama, since 

 the pedigreed lines of Yokohama, though i)lanted late, had finished 

 flowering. In the cross of Velvet by China in 1912, the one parent 

 Velvet plant belonged to the above-mentioned pedigreed line, while the 

 pollen came from more than one plant of a pedigreed line of China 

 bean. All the China bean plants at the Station, and presumably all in 

 Florida, came however from a single seed. 



Fig. 4. Pod of China bean. Natui-al size. 



In the second generation of the Velvet-Lyon cross, the progenies 

 of the different first-generation plants were kept separate. No differ- 

 ences were found between them. In the second generation of the Lyon- 

 Velvet cross, the plan of experiment (see Report of the Florida Station 

 for 1912) did not permit of this. All the seeds which were sown in 

 1913 of the Velvet-Yokohama cross came from one first-generation plant. 



The selection of pedigreed lines of these four parent plants for 

 crossing is in a measure supererogatory, since, with the one exception 

 noted above, I have as yet found no genetic differences witliin the 

 populations. On this is based the abbreviation used in pedigrees. 

 V stands for a Velvet bean parent, L for a Lyon, Y for a Yokohama, 

 and C for a China. The first-generation hybrids are represented by 

 VL, LV, YY, and VC, respectively, the pollen parent being last. If 



