14.6 THE COTTON PLANT IN EGYPT chap. 



definite mode at the light end, consisting of eight plants as 

 against twenty-two in the rest of the curve.^" The 

 extremes of the curve were 0"012 g. and 0"038 g. 

 while the modes were situated at 0"018 g. and 0"032 g. 

 respectively. 



We may reason by analogy that the lint distribution 

 will behave in much the same way as the fuzz-distribution, 

 and may possibly be coupled with it in part. 



Colour of the lint. — The first crosses made between 

 Egyptians with brown lint, and Uplands with white lint, 

 gave an intermediate Fj of creamy hue, with simple 

 1:2:1 ratios in Fj such as 12:21:11; the whites and 

 browns bred true up to the Fj, while the creams 

 broke ap. 



Even in these series there were manifest complications. 



Thus, while never transgressing the limits of " brown- 

 ness," the extracted browns were hj no means uniform, 

 some being much darker than the Afifi parent, while 

 others were lighter. We have not yet decided whether 

 these difi"erences were gametic, or whether they were 

 due to "autogenous fluctuation" with other characters. 



Another cross, that of Charara x King, where the parents 

 were very light brown Egyptian, and white American, gave 

 an intermediate Fj as before, but the Fj consisted of 

 '■ 9 brownish : 60 creamy : 109 white." This classification 

 was made by a cotton expert, and not by the author. It 

 is curiously reminiscent of the inheritance of petal spot, 

 with its suggestion of gametic coupling. 



The lint from F3 of this family, and from all other 

 families grown since, has never been examined by an 

 expert, and since this is peculiarly a case where outside 

 judgments are best, the author prefers to leave the 

 discussion at this stage. 



The "style" of the lint. — At present we are 

 completely in the dark as to the real nature of the 

 differences between such lints as Upland and Egyptian. 



