272 
Journal of Agricultural Research 
Vol. XXVII, No. S 
in which the soil is rich in inorganic solutes, it seemed essential to dis¬ 
tribute the Egyptian and Upland cottons and their F x hybrids uniformly 
over the field. 
The plan adopted is shown in figure i. Here the heavy line indicates 
Pima Egyptian, the broken line indicates Meade Upland, the light solid 
line indicates Acala Upland, and H denotes a hybrid plant. Beginning 
at the south end of the field, io feet of each row was planted to Pima 
cotton. On four of the rows (i, 3, 5, and 7) one hill of hybrid was 
planted. On the first and fifth row self-fertilized Pima and Meade seed 
was used. For the other rows bulk seed was employed. 
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Fig. 1.—Planting scheme for comparison of Upland and Egyptian cottons and their Fi hybrid. Only 
the two ends of the plot are shown. The heavy solid line represents plants of Pima Egyptian, the broken 
. line plants of Meade Upland, the light solid line plants of Acala Upland, and the letter H an Fi hybrid 
plant. The term duplet is used to designate plants of Egyptian and Upland which are contiguous and 
in the same row. The term triplet designates an Ft plant (H) having Egyptian plants on one side and 
Upland plants on the other, all in the same row. 
The Pima cotton and the hybrid, when it occurred, was then followed 
by 20 feet of Upland cotton, which was followed by 20 feet of Pima on 
rows 2, 4, and 6, and by a hybrid plant, and then by slightly less than 20 
feet of Pima on rows 1, 3, 5, and 7. Thus the length of the plot afforded 
space in each row for 9 subrows, each of 20 feet, and for 2 half-subrows, 
each of 10 feet, of Pima cotton, and for 10 subrows, each of 20 feet, of 
Upland cotton. In the rows which contained hybrid plants the space 
for the Pima and Upland subrows was slightly shortened to make room 
for the hybrid hills. The spacing in the rows of the individual plants 
of all varieties and hybrids was identical. 
This plan distributed plants of all types to be compared uniformly 
over the entire field. Collections were made at the 20 points of contact 
of Egyptian and Upland cotton or of Egyptian, hybrid, and Upland 
cotton in each of the rows. The hybrid plant and the contiguous Egypt¬ 
ian and Upland plants are designated as a triplet. The contiguous 
plants of Egyptian and Upland cotton in the rows containing no hybrid 
individuals are conveniently designated as a duplet. 
