V FLUCTUATION loi 



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

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

 slight, negative. 



None of these are 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, takgi plant by plant {e.g., 

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

 (r = 0-8l). 



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 (Tent, 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, with a P.E. of it 3" 5 per cent. 

 This is probably an excessively high figure, as the plauts 

 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). 



