HARRIS: TETRACOTYLEDONOUS RACE OF PHASEOLUS VULGARIS 239 



Thus there is really very great difficulty in determining which 

 simple leaves should be counted as belonging to the primordial 

 ones. What one would like to do would be to include only these 

 which were laid down in the seed. This we tried to do. 



Diagram 2. Frequency distribution of number of primordial leaves per plant. 



The distribution of the number of leaves per plant is given in 

 the totals of tables II and III and represented graphically in 



DIAGRAM 2. 



Inspection of the totals- of the tables shows that number of 

 leaves has a far wider range of variation than number of coty- 

 ledons. In both cases the greatest frequency falls upon four. In 

 both cases the distributions are decidedly asymmetrical. In the 

 case of the leaves, however, the mean falls above the mode — in 



