1 v I 



LOCK : STl'DIKS [N PLANT BREEDING 



The above table shows a very wide range in the percentage 

 number of grains in which the blue colour is dominant, but 

 in no case does the number approach the possible maximum, 

 namely 50 per cent. 



Expt. 66. — We pass now to a consideration of the offspring 

 of the blue grains of F 2 - Out of every 55 blue grains in F 2 we 

 expect 25 to be of the constitution blue x blue, and the remain- 

 ing 30 to be heterozygotes. making up a total of 50 heterozy- 

 ^otes when added to the 20 white grains out of a total of 15 

 white, already shown to be of that nature. 



The offspring of the blue grains pollinated by white dent 

 • i- Follows in F v 



73 plants were obtained, of which 10 bore blue grains 

 exclusively, whilst the remainder produced both blue and 

 white grains in varying proportions. These proportions 

 were determined in the case of the 36 finest cobs — each 

 from a separate plant — all the other cobs being more or less 

 imperfect. The result of this determination is shown in 

 l tble 41. 



