SoME PROPERTIES OF THE WHEAT KERNEL. 51 



It thus becomes very apparent that the percentage of nitrogen is 

 relatively greater in the light wheat selected in the manner described. 



It is well known that immature wheat is of lighter weight than 

 mature wheat and that it contains a greater percentage of nonproteid 

 nitrogen. In a field of wheat there are always certain plants that 

 mature early, others that mature late, and some that never reach a 

 normal state of maturity. The last condition is very likely to occur 

 in a region of limited rainfall and intense summer heat. The con- 

 ditions most favorable for the filling out of the grain are shown to be 

 an abundance of soil moisture and a fair degree of warmth. The 

 more nearly the conditions are the reverse of this the more shriveled 

 the kernel and the lighter the weight. In the same variety and in 

 the same field there are kernels that are small and shriveled because 

 of immaturity, disease, or lack of nutriment. All of these classes 

 would appear among the " light" kernels separated in this way. 



In order to approach the question from another standpoint, a num- 

 ber of spikes of wheat of the Turkish Red variety were selected in the 

 field, care being taken that all were fully ripe, and that they were 

 composed of healthy, well-formed kernels. These spikes were sam- 

 pled by removing one row of spikelets from each spike and the kernels 

 so removed were tested for moisture, proteid nitrogen, specific 

 gravity, and weight of kernel, and from the last two the relative 

 volume was calculated. It will be shown later that a sample taken 

 in this way permits of an accurate estimation of the average com- 

 position of the kernels on the spike. 



The number of grams of proteid nitrogen in the row of spikelets 

 on each spike was calculated from the data mentioned, and the 

 average weight of the kernels on the row of spikelets was determined 

 from their total weight and number, thus permitting of the estima- 

 tion of the number of grams of proteid nitrogen in the average kernel 

 on ea-ch spike. 



In Table 4 the spikes having a proteid nitrogen content of from 2 to 

 2.5 per cent are arranged in one group, and on the same line with each 

 spike are placed the number of kernels on one row of spikelets, weight 

 of these kernels, weight of average kernel, relative volume of average 

 kernel, specific gravity of kernel, grams of proteid nitrogen in one 

 row of spikelets, and grams of proteid nitrogen in average kernel. 

 Spikes having a proteid nitrogen content of from 2.5 to 3 per cent are 

 similarly arranged, and so with all spikes up to 4 per cent. The aver- 

 age for each group is shown in the table. 



There are, in all, 257 spikes, of which 18 have from 2 to 2.5 per cent 

 proteid nitrogen. 82 from 2.5 to 3 per cent, 107 from 3 to 3.5 per cent, 

 and 49 from 3.5 to 4 per cent. 



