146 



LOCK : STUDIES IN PLANT BREF.DIM; 



number of grains must be of that nature, and 75 per cent, of 

 the whole number are white. 



The point can be tested by sowing the white grains and once 

 more pollinating by white. From cob No. 12 of table 36, which 

 contained just 76 per cent, of white grains, a number of both 

 white and blue grains were sown separately, and pollination 

 was effected from a white dent form. 



If Mendel's law holds good we must expect 50 out of 76 of 

 the white F 2 grains to be pure white homozygotes, whilst the 

 remaining 26 will be heterozygotes in which white was domi- 

 nant — making up 50 per cent, of the original total when added 

 to 24, which is the number of grains already known to be 

 heterozygotes from their external appearance. 



F3. 



h.i pi. 63. — The actual offspring of the white F 2 grains was 

 as follows in F s , 1 cob being gathered from each of 37 plants :— 

 23 cobs bore white grains exclusively. 

 4 cobs bore from 1 to 4 blue grains, the rest being white. 

 10 cobs bore from 17 to 5-7 per cent, of blue grains. 

 i.e., 12 or more in each cob. 



Details regarding these last 14 cobs are given in Table 37 : — 



Table 37. 



Whit.-. 



mm-. 



i 



.' 

 :; 

 i 

 5 

 6 

 7 



B 

 10 



M 

 12 

 L3 



It 



omittiug 

 II to ll 



I 



176 



580 



t22 



542 



585 



632 



568 



53 1 



680 



579 



711 



5 1 2 



190 



630 



546 



5,830 



Per cenl . 

 Mine. 



26 ' 7 



22 • ."- 



8-5 



7- t 



5 9 



6 • 2 

 5*6 

 2 -4 

 2 ■ 2 

 1-7 



8-0 



