F. KiDD AND (\ West 



1:25 



Table IV. 



Barley 



Wheat 



No. of spikelet 



(from base of ear 



upwards) 



Spikelets 1- 9 

 10-18 

 19-27 



No. of 

 seeds 



27 



Total air-dry 



weight in 



milligrams 



of seeds 



426 mg. 



828 



512 



Total root-length 



in millimetres 



after 5 days in 



gerniinator 



670 mm. 

 3281 

 1364 



Total air-dry 



weight in' 



milligrams 



of seeds 



. loS mg. 

 282 

 191 



Total root-length 



in millimetres 



after 5 days in 



gerniinator 



223 mm. 

 1094 

 454 



It is unfortunate that Nobbe's experiments were not carried further 

 to determine whether the plants which he obtained from his larger seed 

 would continue to show throughout their development a superiority over 

 those obtained from the smaller seed and would finally produce a larger 

 yield. This point, however, has since been investigated by Bolley and 

 by Richardson and Green. Bolley (i) in the course of a series of experi- 

 ments extending over four years to test the difference in yield when 

 plump grains of large size and plump grains of small size were selected 

 for seed, found that "perfect grains of large size and greatest weight 

 produce better plants than perfect grains of small size and light weight, 

 even when the grains come from the same head." 



Richardson and Green (62) carefully analysed a large number of heads 

 of wheat and found the heaviest grains in the middle of the ear. They 

 found, however, a complication due to the fact that the median grain 

 of each spikelet tended to suffer in its development with the result that 

 the median grains were almost always lesser in weight and, if they 

 happened to germinate, gave rise to inferior plants. 



The following table gives their results in comparing both percentage 

 of germination and yield for the heavier grains from the central region 

 of the ear with that for the lighter grains from the tip and base of the 

 ear together with the median ones from the central region. 



Table V. 



Comparison of Yield of Produce from median* grains together with the 

 light grains at either extremity of the head with that from heavy grains. 



