r\ THE TROPICS : Itt. II'! 



starchy type which made up nearly 50 per cent, of the 

 total. 



F 3. 



Offspring of Plant No. 1, Table 5: — (a) smooth, (b) fully 

 wrinkled, and (c) slightly rough grains were sown. After 

 removal of the male flowers the plants were freely exposed 

 to the pollen of G. W. S. 



{a) Expt. 22. — Twenty plants were examined. In every 

 case the cobs showed approximately equal numbers of 

 starchy and sugary grains. The three largest gave the 

 following numbers : — 



Table 7. 



... , Per cent. Per cent 



Plant. Starchy. Sugary. Dotal. starchy. Sugary 



1 .. 217 .. 216 .. 433 .. 50-2 .. 49-8 



2 .. 159 .. 177 .. 336 .. 473 .. 527 



3 .. 188 .. 198 .. 386 .. 48- 7 .. 51 3 



Total 564 591 1,155 48 8 51 2 



Expectation : 50 starchy : 50 sugary. 

 All the grains counted as sugary were well wrinkled. 



(b) Expt. 23. — Twenty plants produced only sugary grains, 

 over 6.000 in number. 



(c) Expt. 24. — Out of a total of 19 plants, 18 produced 

 sugary grains only, the remaining plant yielded 148 st.. 140 su., 

 or 51*4 per cent, of the former. 



F 4. 



In this generation a large number of recessive grains were 

 grown— the offspring of plants described in several of the 

 above experiments, and in particular of experiments 22, 23. 

 24. Such recessive grains yielded without exception recessive 

 offspring. 



2.— YELLOW VARIETIES CROSSED WITH WHITE VARIETIES. 



Here the colour of the hcterozygote grains was usually 

 more or less intermediate between the parental colours. In 



