X'AKIATION and Co-rUliLATlON IN TlMOTHV. 



459 



TABLE VI — Three-Year Record of Individuals Lowest in Height in 1907 



Height in Inches 



Plant Number 



109 .02 

 27.06 

 42.23 

 4423 



52 03 



96.01 



149.24 



In nearly every instance these plants were located near one end of 

 the row where conditions were so unfavorable that many individuals 

 had been killed out, thus showing that, in this particular case, adverse 

 soil conditions were instrumental in bringing about skewness. 



There is another set of changes that take place in the population 

 which are undoubtedly factors in producing skewness. It has been 

 observed that certain individuals reach their maximum development 

 at an early age and then gradually decline while others mature at a 

 later period. It is highly improbable th'at an equal number of individuals 

 is thus affected in both instances. 



In the case of weight we find positive skewness which decreases each 

 year. This is attributed to the same factors that produced the skew- 

 ness in the curves for height. 



TABLE VII — Coefficients of Correlation 



Earliness and height 



EarHness and weight 



Duration of bloom and height 

 Duration of bloom and weight 

 Weight and height 



1905 



.052 ± .011 

 .119 ± .011 

 052 ± .01 1 

 .192 ± .011 

 • 274 ± .01 1 



1906 



108 ± .011 

 047 ± .011 

 004 ±.011 

 042 ± .01 1 

 454 ± -009 



1907 



-.236 ± .011 

 -.186 db .011 

 -.138 ± .011 

 -154 ± .oil 

 .718 ± .006 



It will be seen by reference to Table VII that there were well-defined 

 changes from year to year in the coefficients of correlation and that in 



