IN THE TROPICS: III. 



109 



grain belonged to the starchy or to the sugary category. The 

 starchy grains showed no alteration in shape or consistency 

 from those born by the parental type. The sugary grains 

 differed a little in shape owing to the fact that the cobs, each 

 taken as a whole, showed some dominance of the shape cha- 

 racteristic of the flint variety. 



2. — The result of crossing F1 Plants with a Dominant Form. 



Expt. 15: — {Yellow dent x White dent) x (White dent x 

 Black Mexican). 



Thirteen cobs bearing altogether 5,431 grains were examined. 

 All the grains were of a fully indented type and showed no trace 

 of the sugary parent. 



Expt. 16. — (While dent x Black Mexican) x White 

 dent. 



Nine cobs bearing 2,992 grains were examined. All the grains 

 were alike, being starchy and intermediate between the flint 

 and dent types. 



Expt. 17. — (Yellow flint x Black Mexican) x White 

 flint. 



Nine cobs with 2,412 grains were examined. All the grains 

 were found to be of the full flint type. 



3.— The result of crossing F1 Plants with a Recessive Form. 

 Expt. 18.— (Yellow pop corn x G.W.S.) x G.W.S. 



Table 3. 



Sugary 



217 

 204 

 198 

 230 

 201 

 133 

 165 

 209 

 224 

 165 



Total 2,018 



1,946 



3,964 



510 



49-0 



