G90 



THE AMERICAN NATURALIST [Vol. XL V 



errors. It will be noted at once that for all the char- 

 acters the mean is higher in 1909 9 — indeed for some 

 characters in the "Kapital Erbse" it is almost double 

 that found in 1908! With one exception the standard 



TABLE I 











08 and 1909 Popi 









SUndard 



















!jl 





Wdght of Plant 

 1908 Population 



13.09 

 20.82 



7.99 

 20.39 



6.' 568 



2.815 

 7.127 



32.47 



34.95 



1909/1908 Katio 

 Length of Stem 



1.59 

 114.96 



78.96 

 158.42 



1.545 

 1031 



2.531 

 12.575 



.97 



JLL93_ 



.99 

 12.73 



1909/1908 Ratio 

 Thickness of Stem 

 1908 Population 



1.19 



25 20 



2.01 

 20.50 



1.257 



So 



1.603 

 1933 



11.50 

 9.48 



T80~ 

 12.19 



1909/1908 Eatio 

 Number of Pods 

 ' 1909 P ° pU !f Uon 



1.05 



4.59 

 6.48 



1.17 



5.62 

 11.54 



.864 

 1.987 



1.409 



1.805 

 4.263 



.82 

 30.66 



1.20 

 36.95 



1909/1908 Eatio 

 Weight of Pods 



1908 Population 



1909 " 



1.41 



9.71 



2.05 

 lo!26 



1.456 

 4.111 



2.361 



2.184 

 4.407 



32.80 

 3S.03 



1.15 



37.95 

 42.98 



1909/1908 Eatio 

 Number of Seeds 

 1908 Population 

 1909 



1.16 



19.64 

 26.60 



~ 1.78 



24.02 

 45.11 



1.343 

 6.267 



2.017 



8.418 

 18.633 



1.16 



:-;-!' 44 



1.13 



35.05 

 41.31 



1909/1908 Ratio 

 Weight of Seeds 

 1908 Population 

 1909 



1.35 



7.63 

 8.56 



4.56 

 7.26 



2.569 

 3.511 



3.376 



1.08 



33.67 

 40.99 



40.21 

 46.49 



1909/1908 Eatio 



1.12 



1.59 





1.841 



1.22 



1.16 



deviations in 1909 are higher than those in 1908. Mean 

 and standard deviation are generally closely correlated, 

 and this doubtless accounts for the greater variability 

 of the 1909 series. Possibly, however, the 1909 plants 



