1903.] BAILEY—MOVEMENT IN PLANT-BREEDING. 59 
‘2, That there is a wide variation in the chemical composition 
of different ears, even of the same variety of corn. These two facts 
are well illustrated in Table 1. 
TABLE I. PROTEIN IN SINGLE KERNELS. 
Ear A, Lar B, Banics Ear D, 
protein, protein, protein, protein, 
per cent. per cent. per cent. percent, 
BEC LING) MC ore 6c nie mraicinl reo 12.46 11.53 7-45 8.72 
UO io Ca ogee aetna ot 12.54 12.32 7.54 8.41 
i Oy 8 B54 ANA 6 salon 12.44 12.19 7.69 8.73 
6 Soe GR aon oO Sear 12.50 12.54 7.47 8.31 
“e RON Nal Oe Mea ene) E2230 12.14 7.74 9.02 
ce COTE | (eines as pF 12.49 12.95 8.70 8.76 
<s CO LURES eae te Pe 12.50 12.84 8.46 8.89 
Re ee x sleistea epee ae 12.14 8.69 9.02 
“ Sot Oia\aiesains,9 eine sha os 12.14 12.04 8.86 8.96 
cs SEU ERT Os) artshoieteter ois se icve ts 12.71 L275 8.10 8.89 
‘‘Tt will be observed that while there are, of course, small 
differences among the different. kernels of the same ear, yet each 
ear has an individuality as a whole, the difference in composition 
between different ears being much more marked than between 
different kernels of the same ear. 
‘‘ The uniformity of the individual ear makes it possible to esti- 
mate or to determine the composition of the corn by the examin- 
ation or analysis of a few kernels: The remainder of the kernels 
on the ear may then be planted if desired. The wide variation in 
the composition between different ears furnishes a starting-point for 
the selection of seed in any of the several different lines of 
desired improvement. 
‘‘The methods of making a chemical selection of ears of seed 
corn by a simple mechanical examination of the kernels is based 
upon the fact that the kernel of corn is not homogeneous in struc- 
ture, but consists of several distinct and readily observable parts of 
markedly different chemical composition (see illustrations). Aside 
from the hull which surrounds the kernel, there are three principal 
parts in a grain of corn: 
“¢1, The darker colored and rather hard and horny layer lying 
next to the hull, principally in the edges and toward the tip end of 
the kernel, where it is about three millimeters, or one-eighth of an 
inch, in thickness. 
1 Determination lost by accident. 
