PARNELL, KANGASWAMI AYYANGAR, AND RAMIAH 105 



Other families from the same parent gave a .simple 3 : 1 ratio of yigmented, 

 red rice : un pigmented, grey-hroivn rice and further analysis of some of the 

 families given in the second half of Table XX shows that the same occurred 

 there. 



The most simple and probable explanation of this is that a single red rice 

 factor is concerned, and that this is only able to produce the full-red colour in 

 the presence of the par-ticular purple pigmentation factor that is segregating 

 in this group ; in the absence of this pigmentation factor the red rice factor 

 gives grey-brown. 



The existence of unpigniented varieties with red rice would be explained 

 on the assumption that they lack the other of the two pigmentation factors 

 which have already been shown to exist. If this theory is correct crosses 

 between unpigmented red-riced varieties and the above grey-brown type 

 should give a pigmented red-riced F], and F^ should show segregation for both 

 pigmentation factors. This will be tested in due course. 



It was found that, owing to the rice-colour not developing properly till 

 the grain is dead ripe, it was better to note this character in the field, leaving 

 each plant till it was absolutely definite, rather than to take one head from 

 each plant when the crop was ripe. The latter method no doubt accounts for 

 much of the irregularity of the numbers in Table XX. 



F. K. P. 



June, 1917. 



