IN THE TROPICS : III. 



137 



which bore the yellow and blue characters. Other plants again 

 produced grains with a red pericarp, but these as well as the 

 blue grains may be at present disregarded. 



F2. 



Ezpt. 57. — In order to test the point as to their origin, a 

 number of the above yellow grains were sown in a plot 

 where pollination was effected from plants produced from 

 the white grains of the same cobs. These white grains 

 proved to be true extracted recessives, since less than one 

 per thousand of the whole number of grains produced by 

 them were yellow or blue, and these are to be accounted for 

 by accidental escape of pollen from the crossed plants grown 

 on the same plot. Many of these white recessives were, 

 however, impure in respect of the red pericarp character not 

 visible as the immediate result of crossing, and consequently 

 a considerable number of red coated cobs were produced by 

 them. Some of the supposed white x yellow plants with which 

 we are now dealing showed the same character. Of those in 

 whicli the pericarp was white the following were counted : — 



Table 31. 



Plant 



1 



2 

 3 

 4 

 5 

 (i 

 7 

 8 

 9 



Blue. 



6 



3 



Total 1,982 



1,963 



10 



3,955 



49-6 



Expectation : 50 yellow 50 white. 



The intensity of colour in the yellow grains varied to some 

 extent on different plants, but the grains on any given cob 

 were very uniform in this respect. The two kinds — white 

 and yellow — could be distinguished easily and rapidly. 



