H. M. Leake 45 



The material on which the preliminary determinations, here dealt 

 with, have been made consists of 232 samples derived from a wide series 

 of plants of the Asiatic series cottons, and covers, as far as possible, the 

 full range of variation found. Full details cannot be given here, but a 

 few typical instances illustrating the range may be recorded. 



These few illustrations are sufficient to indicate the wide degree of 

 variation found in the characters under consideration, and it is note- 

 worthy that there appears to be no direct relation between the ginning 

 percent and any of the remaining characters, even in the selected series 

 here given. That this must be so is again illustrated by abstract 

 consideration. I am indebted to Mr Udny Yule for the following 

 formula which indicates the relation between the four characters 

 concerned : 



number of fibres per seed x wt. of 1000 fibres 



where k = r r j • 



volume 01 one seed 



From this it is clear that the ginning percent cannot be directly 

 measured from any single one of the characters here dealt with. It is 

 necessary, therefore, to proceed further and calculate the coefficients of 

 correlation. 



For this purpose the characters may be numbered as follows : 



(1) Ginning percent, 



(2) Number of fibres per seed, 



(3) Wt. of 1000 fibres, 



(4) Volume of seed. 



The correlations between these characters are found to be 



