IX THE TROPICS : III. 



115 



F 2. 

 The result of crossing F 1 Plants with the " Recessive." 



Expt. 28.— {White dent x Yellow dent) x White dent. - 



Table 8. 



Total 1,070 



998 



2,068 



5174 



48-26 



Expectation : 50 yellow ; 50 white. 

 Expt. 29. — [Yellow dent x White dent) x White dent. 



Table 9. 



Total 1,354 



1,420 



•2.77 4 



48-8 



512 



Expectation : 50 yellow : 50 white 

 Expts. 28 and 29. — In both these cases the resultinor " yellow" 

 grains closely resembled those which were obtained from the 

 first cross — white x yellow — in F ] . The colour was rather 

 more variable, and perhaps on the whole slightly darker, hut 

 was much nearer to that mentioned than to the result of the 

 reciprocal cross in F 1 . 



Expt. 30.— (Yelloiv dent x White dent) x {White dent x 

 Black Mexican). 



A considerable number of the grains produced had a black 

 or blackish aleurone layer (see Expt. 40) and in these the 

 colour of the underlying endosperm was usually not distin- 

 guishable. The following table includes only those grains 

 which showed no black pigment in the aleurone layer. 



