IMPROVEMENT OF MAIZE I9I 



^58. -fir^ding for Composition. — Hopkins found that when 

 analyses "Axre made of different samples coming from a consid- 

 erable number of ears that the composition of the grain was 

 quite uniform. When, however, samples were taken separately, 

 ^ven from different ears of the same variety, there were consid- 

 erable differences in the composition. Some variation was found 

 in the composition of grains from the butt, middle and tip third 

 of the ear, but when one or more rows were taken throughout 

 the whole length of the ear the composition of this sample was 

 found quite accurately to represent the whole ear. He further 

 established the fact that if the grains of ears varying in com- 

 position were grown separately, this difference in composition 

 Would be found in the resulting crop. It was thus established 

 that composition was hereditar}'. He also showed that the com- 

 position would be determined in considerable measure by the 

 physical distribution of the parts of the grain. 



259. Breeding for Fat. — As thirty-five per cent of the embryo 

 is fat and as eighty to eighty-five per cent of all the fat of the 

 grain is in the embr)-o, it is evident that grain with large 

 embr}"OS would contain larger percentages of fat than those 

 containing small embr}^os, unless the per cent of fat in the 

 embr)^o itself varied largely.^ 



Beginning with the same variety of maize, ears were selected 

 four years for high fat and low fat content. Then rows were 

 planted with both kinds of maize, every hill having each kind 

 of maize just far enough apart to identify the stalks. Thus 

 they were grown in the same season, in the same soil and 

 under the same cultivation. The resulting crop from maize 

 selected for low fat content contained three and eight-tenths 

 per cent of fat; that for high fat, five and eight-tenths per cent 

 of fat.^ In other instances there have been brought about 



1 The investigations of Hopkins appear to show that large embrj'os contain a 

 larger percentage of fat than small embryos. 111. Bui. 87, p. 105. 

 2 111. BuL 87, p. lOOw 



