18 



Lyon (39) cites Tollny as objecting to experiments by a number 

 of experimenters with various cereals in which almost without 

 exception kernels of high specific gravity produced the beet 

 yields, because no distinction was made between absolute 

 wiight and specific gravity in the kernels. He claims that 

 the value of the seeds lies in the kernels of absolute 

 heavy weight rather than in kernels of high specific gravity, 

 concluding that the specific gravity of the seed exerts no 

 influence on the yield. Lyon goes on to say that in the light 

 of the experiments that have been conducted it would seem 

 that there is a difference between seed of low specific grav- 

 ity and high specific gravity in favor of the dense seed, but 

 there is little difference between seed of high and medium 

 specific gravity. 



Relation of Size and height of Kernel 

 to Composition. 



It is not the purpose of this thesis to enter far 

 into this phase of the large seed factor. Therefore only 

 brief reference will be made. 



Lyon (40) concludes that in general it may be said that 

 as between wheat kernels of the same variety grown in the 

 same season and upon the same soil, the specific gravity is 

 inversely proportional to the nitrogen content. This conclu- 

 sion is given after citing several experimenters who pre- 

 sent varying results. He suggests that as the ash, which 

 varies so considerably with the soil on which the wheat is 

 grown, has such a high specific gravity compared to that of 

 the other constituents this would prevent the establishment 

 of a constant relation. H further suggests that the number 



and size of vacuoles would affect the specific gravity. 



