VaUIATIOX AM) CoKUKLATION IN TiMOTllY. 



455 



mean values to have been highest in 1906, with 1907 next in order. 

 The standard deviation was lowest in 1905 and highest in 1907. 



Place variation in weight. — The curves for weight (Fig. 143) show 

 a higher degree of conformity for the three years than in the case of any 

 of the other characters for which statistical data were taken. It will 

 be seen, however, that there was a slight decrease in range from year 

 to year, also changes in the position of the empirical modes. In 1905 

 the modes were at 38 and 53, in 1906 at 48 and 63, and in 1907 at ^^ 

 and 43. While the inaximum individual weight was reached in 1905, 

 the highest average or mean was in 1906, with 1905 next in order. The 

 standard deviation was highest in 1905, with 1907 closely following. 



From the data presented, it is plainly evident that in timothy there 

 is a well-defined change in the distribution from year to year. It has 

 been pointed out that characters relating to bloom are influenced to a 

 large extent by climatic conditions. This also appears to hold true 

 for height and weight, though in these cases the response to environ- 

 mental influences is less marked. Referring to the table of constants 

 (Table V) we find that the highest mean values for the two characters 

 last named were obtained in 1906, which was an exceptionally favorable 

 season for the growth of timothy. 



TABLE V — Constants for Timothy 



Mean 



Standard 

 Deviation 



Coefficient of 

 Variability 



Earliness 



i9o.=5 



1906 



1907 



Duration of bloom 



1905 



1006 



1907 



Height 



1905 



1906 



1907 



Weight 



1905 



1906 



1907 



7.594 ± .024 

 7.052 ± .019 

 7 346 ± 021 



.142 ± 

 ,663 ± 



.017 

 .oi-j 



1.853 ± .015 



28, 



23' 



25. 



21 

 22 



± -244 

 ± .200 

 ± .216 



10.477 ± 

 15. 116 ± 

 12.858 ± 



.028 

 .022 

 .022 



2 .425 ± .020 

 I .951 ± .016 

 I 956 ± .016 



35.910 ± .045 

 40 . 198 ± .048 

 39-318 ± .053 



3.97s ± .032 

 4.212 ± .034 



4 . 63 1 ± . 03 7 



23 

 12 



15 



.15 ± .196 

 .91 ± .106 

 .21 ± .125 



11.07 ± .090 

 10.48 ± .085 

 11.78 d: 096 



4.=>-663 ± 

 47897 ± 

 41 .919 ± 



,229 



,200 

 .221 



20.056 ± .162 

 17-520 ± .141 

 19425 ± -156 



43-92 ± .41 

 36-58 dt .332 

 46.34 ± .447 



