170 



EXPERIMENT STATION. 



[Jan. 



An inspection of the graphs will show that this is the actual 

 result. The curves for 1908 show smaller plants with fewer 

 pods, but there is, nevertheless, a very striking similarity in the 

 scope and character of variation in the two years. (See Figs. 

 1, 2 and 3.) 



The general character of the results may also be seen from the 



following table : 



Variation in Peas. 



179 vines studied in 1907; 225 vines studied in 1908. 



Dljferences in Yariability. 



A striking feature in this experiment — as in most others of 

 a similar sort — comes out in the marked differences of varia- 

 bility in different groups of progeny. Eor example, if we con- 

 sider the total product in peas per vine, we may compute that 

 the progeny of parent C showed more than double the amount 

 of variation found among the progeny of parent B or J. These 

 figures are so interesting that they are given in full in the fol- 

 lowing table. (Coefficient of variability is equal to standard 

 deviation divided by the mean.) 



