v FLUCTUATION 101 



some, positive ; Height, doubtful, positive ; Lint-length, 

 slight, negative ; Lint- weight, high, positive ; First-flower, 

 slight, negative. 



None of these arc very definite and the explanation lies 

 in the fact that while height, leaf-length, and first-flower 

 represent the mean result of a long period of environmental 

 influence, the fluctuation in weight for any particular seed 

 is probably fixed within a period of a few days. 



The same explanation applies to the high P.E. of uniform 

 families, which is nearly equal to that of the most irregular 

 families. 



Summarising, we may say that everything points to the 

 root as "the controller of fluctuation in seed-weight. 



Lint-weight and out-turn. We have already dealt 

 with the correlation between weight of lint and seed, in 

 discussing ginning out-turns. The correlation is 

 less close in pure strains, taken plant by plant (e.g. 

 r = 072) than for the crop-samples there mentioned 

 (r =-- 0-81). 



The fluctuation in lint-weight seems to be proportionally 

 less than that in seed- weight, the P.E. being, e.g., 7'5 

 per cent, as against 8 '3 per cent, respectively in the same 

 family. This statement probably requires revision for 

 field crop conditions, since wide-sown plants give 

 abnormally low ginning out-turns ; the crop-samples gave 

 a lower correlation between seed-weight and out-turn 

 (0-220 0-094) than between lint- weight and out-turn 

 (0-316+ -091).* 



The fluctuation in ginning out-turn for family " 77 " 

 had a mean of 92 rotls, Vith a P.E. of 35 per cent. 

 This is probably an excessively high figure, as the plants 

 growing in the tanks gave much higher out-turns than the 

 rest. 



Seed fuzz. Although this amount of " fuzz " on 



* See Craig, J. I. (3). 



