TN THE TROPICS : III. 



Mil 



A considerable proportion of the grains included under 

 the heading " Black" in the above table were mottled in 

 appearance, showing darker spots on a paler ground. These. 

 as well as the uniformly coloured grains, ranged from deep 

 black to very pale slate colour, the majority being dark. 

 In later generations the mottling almost entirely disappeared, 

 and the grains recorded as black or blue were also of a more 

 uniformly dark shade of colour. It was found impossible to 

 draw any sharp distinction between the darker and paler grains , 

 and an attempt to examine their progeny separately failed almost 

 entirely owing to failure of the crop. A few of the mottled F 2 

 grains which were sown separately yielded in F§ — on pollination 

 by G. W. S. — a mixture of blue and white grains among which 

 the blues were now almost uniform in appearance. 



It may be remarked that the ratio of blacks to whites was 

 the same in the case of starchy grains as in that of sugary 

 grains, the percentages derived from the total figures being 



as* follows :— 



Black starchy .. ..42-99 



White starchy .. ..32-06 



Black sugary . . 14 * 27 



White sugary . . . . 10-67 



And the proportionate number of mottled grains seemed 



to be nearly the same in either case. 



2. — Heterozygotes crossed with Pollen from the Recessive Form. 



Ezpt. 39. — ( White dent x Black Mexican ) x White dent. 



Table 14. 



Bin ok. 



White. 



1 



2 



3 



4 



5 



6 



7 



8 



9 



Total.. 974 



2,018 



2,992 



32-6 



67 4 



9(8)06 



(4) 



