For convenience we use the term "sire seed," or "sire ears," to designate the ears that are to be planted in odd-numbered rows to produce tassels. (the male flowers) and to furnish pollen ; and we use the term "dam seed,' or "dam ears," to desig nate the ears to be planted in the even-num bered rows to produce future seed ears. Of the four seed ears taken from each selected field row, two are used for sire seed and two for dam seed.
In the column headed, "Guide system for even years," is given a key or guide by which to work out the actual plan for planting in all even numbered years ; and under the heading, "Model example for an even year," is given an actual plan which has been worked out, using four seed ears from six selected rows from each quarter of the breeding plot.
In the guide system. for the sake of simplic ity, we use four seed ears from each of the first six even-numbered rows in each quarter, a selection which would probably never occur in actual practice. It will be observed that the dam seed ears for each quar ter are ears which grew in the same quarter, while the sire seed is always brought from an other quarter. For the first quarter (rows 1 to 24), sire ears are brought from the fourth quarter. For the second quarter, sire seed is brought from the third. In each of these cases sire seed is carried diag onally across the breeding plot. For the third quarter sire seed is brought from the first quarter, and for the fourth, from the second, the sire seed being carried lengthwise of the breeding plot in these cases.
It will also be observed that there is a definite order of planting for "even years" and another definite order for "odd years." Thus, in the first quarter, the even-numbered rows are planted in ascending order with dam seed selected from rows numbered : 2, 6, 10, 4, 8, 12, 2, 6, 10, 4, 8, 12. The alternating even numbers are repeated in sets of three and six. The odd-numbered rows are planted with sire seed selected from rows numbered : 76, 80, 84, 78, 82, 86, 78, 82, 86, 76, 80, 84. This is the same order as for the dams except that the two sets of three are reversed in the second set of six. The only change required for odd-numbered years is to transpose the two sets of six in plant ing the sire seed. Exactly the same system is used
in each quarter of the breeding plot.
Arranging seed ears for planting.
By referring to the "Model example for an even year," it will be seen that it becomes an easy mat ter to follow the "guide system" in arranging seed ears for planting. Suppose, for example, that in 1905 the best six rows in the first quarter of the breeding plot are 4, 8, 10, 14, 16, 20. Then for the dam seed for planting the first quarter in 1906 these numbers in ascending order are to be substi tuted for the numbers 2, 4, 6, 8, 10, 12, which are given in the "guide system." Thus : For 2, substi tute 4 ; for 4, substitute 8 ; for 6, substitute 10 ; for 8, substitute 14 ; for 10, substitute 16 ; for 12, substitute 20.
Arranging these for planting the field rows, we have : If the best six rows in the fourth quarter of the 1905 breeding plot are 76, 80, 84, 86, 90, 92, then for the sire seed for planting the first quarter in 1906 these numbers are to be substituted in regular order for the numbers 76, 78, 80,82, 84, 86, which are given in the "guide system." Arranging these by threes as indicated in the ''guide system," we have the order for planting the odd-numbered rows in the first quarter : 76, 84, 90, 80, 86, 92, 80, 86, 92, 76, 84, 90. Thus we have both the dam and sire seed ears for the first quarter, arranged exactly as shown under the heading, "model example" in Table I. The seed ears are arranged for each quarter of the breeding plot in a similar way by following the "guide system" and substituting in regular ascending order the actual numbers of the best-yielding rows for the numbers given in the "guide system" in Table I.
With this selection of best rows, as given in the "model example," we would take the best four seed ears from row No. 4 (1905) and plant two as dam ears in rows 2 and 14 and the other two as sire ears in rows 51 and 69 (1906); we would take the four best seed ears from row No. 84 (1905) and plant two as dam ears in rows 78 and 90 and the other two as sire ears in rows 3 and 21 (1906).
In arranging seed ears selected from the 1906 breeding plot for plant ing the 1907 breeding plot, we are to follow the "guide system" for odd-numbered years, again returning to the system for even -num bered years for 1908.