8 



Pearl and Bartlett 



Table II. 



Showing the Analysis, Calculated as Percentage of Total 



Dry Matter, of the Samples of Maize Given in Table P). 



Fj-Progeny 



Fo-Progeny 



Yellow 

 Dent 



9 



White 



Swev-t 



c5 



Yellow 

 Starchy 



Yellow j White | Yellow 



Starchy! Starchy Sweet 



(9) i (3) ' (3) 



White 

 Sweet 



Nitrogen . . 

 Protein . . 

 Crude Fat . 

 Ash ... . 

 Crude Fiber 

 Pentosans . 

 Sucrose . . 

 Dextrose 

 Total Sugars 

 Starch . . . 



1.66 

 10.62 

 4.2S 

 1-59 

 2.19 

 6.89 

 1.56 

 o 



1.56 

 66.48 



1.92 

 12.25 

 9.02 

 2.09 

 2.45 

 7.18 



3-2 1 



1-73 

 4.94 

 58.45 



1.67 

 10.68 

 4-74 

 1.44 

 1.97 

 5.90 

 I. So 

 0.13 



1-93 

 66.24 



1-95 

 12.45 

 9.09 

 1.84 

 2.46 

 8.01 

 4.81 

 3-52 

 8.32 

 54-33 



and striking chemical differences between the two parent forms shown 

 in Tables I and II represent real and typical varietal differences, or 

 are they merely the insignificant and inconstant vagaries of seasonal 

 conditions, random sampling, chemical analysis, etc. ? To the agri- 

 cultural chemist, familiar with material of this class, this question 

 will doubtless seem foolish. The biologist will want evidence, however, 

 since the phenomena with which he is immediately familiar furnishes 

 him no basis on which to form a judgment as to whether, for example, 

 a difference 0.2 or 0.3 percent in nitrogen content is significant or not. 



Table III gives comparative data from which conclusions on these 

 points may be drawn. These data are taken from various compilations 

 which have been published. 



From this table we note at once the following points: 



1. The parent strains of yellow dent and white sweet maize used 

 in these crossing experiments agree in their chemical compositions 

 with average analyses of large numbers of samples of dent and sweet 

 varieties. This agreement is as close as could reasonably be expected, 

 when such facts as environmental influences, random sampling, etc., 

 are taken into consideration. 



2. It is evident that the differences in chemical composition 

 between dent and sweet varieties shown in our parent strains are 

 typical of these varieties in general, and are not of a fortuitous 



1) Only the averages are computed. 



