230 
Journal of Agricultural Research 
Vol. XXI, No. 4 
Measurements were made on one leaf and one boll of each plant, 1 
endeavor having been made to select in each case a leaf and a boll which 
had developed normally and which appeared to be typical of the plant 
in question. Seed cotton was collected from 5 open-pollinated bolls on 
each plant, and the fiber on one seed from each boll was combed out and 
measured, the average of the 5 determinations being taken as the length 
of fiber for the plant in question. The seed cotton was then weighed and 
ginned, the weight of the fiber and the number of seeds in the sample 
were determined, and the lint index (weight in grams of fiber per 100 seeds) 
was calculated from the resulting data. Finally, the seeds were graded in 
respect to fuzziness by matching with a set of types representing the 
total range from the smoothest (grade 1) to the fuzziest (grade 7) condi¬ 
tion of the seed coat. Table I shows for the 12 characters the means 
and coefficients of variation of the three stocks. 
Table I. —Means and coefficients of variation for 12 characters of a progeny of the parent 
plant of the Pima variety , of a “bulk” (continuously open-pollinated) population of 
strain 5~J> and of a line of the same strain which had been strictly self-fertilized during 
five generations 
Means. 
Coefficients of variation. 1 
Character. 
Parent. 
Bulk. 
Selfed. 
Parent. 
Bulk. 
Selfed. 
Leaf length (cm.) 2 
Leaf width (cm.) 3 . 
Leaf index 4 . 
Leaf vein angle 6 .. 
Leaf lobe index 6 .. 
Leaf extension 
169^1. 14 
219 zb 2. 71 
I29±I. 37 
io6dbi. 37 
268±2. 06 
164^2. 27 
2 i 4 ± 3 - 53 
1301k 1. 35 
104 ± 1. 42 
261 ± 1. 64 
167 db 1. 41 
229 zb 2. 09 
i 37 ±i- 11 
ii4±i. 15 
284^2. 38 
5. 4 ±o. 47 
9. 91b .86 
8. 5± .74 
10. 3± .90 
6. i± . 53 
11. 1 db 0. 96 
13. 2±i. 15 
8. 3± . 72 
11. odb . 96 
5. °± .44 
6. 8zbo. 59 
7 - 3 ± - 6 4 
6- 5 ± -56 
8. 1 zb .70 
6. 8 zb . 59 
index 7 . 
19 - 5 ± • 37 
46. 2± . 24 
17. i± .46 
47- i± .21 
20. 5 zb .40 
47 -°± -23 
15- 2±i. 32 
4 - 4 ± . 40 
21. 5±i. 87 
3 - 7 ± • 3 1 
iS- 5 ±i -35 
4 - i± -35 
Boll length (mm.) 
Boll diameter 
(mm.) 8 . 
27 . 3 ± . 14 
59 * 2 ± .33 
40. 8± . 19 
4. 1 ± .06 
3. 8± . 17 
26.91b .08 
57- 3± *28 
44. 6± . 12 
5-6db .05 
4. I db .06 
27. 9± . 07 
59 - 5 ± -33 
42. 9± . 12 
4 * 5 i • °6 
4 - 7 ± • 11 
4 * 2i .35 
4. 6db .39 
3. 8± .32 
13. 2 zb i. 11 
1. 4 ± . 12 
2. 6rb . 22 
4 -Orb .34 
2. 2 zb . 19 
7 . 9 ± -67 
• 5 ± • 04 
2. I ± . l8 
4. 6zb .39 
2. 4zb . 20 
11 . I zb .94 
. 9 zb .08 
Boll index 9 . 
Fiber length (mm.) 
Lint index (gm.). 
Seed fuzziness.... 
1 In the case of seed fuzziness (graded) the standard deviations are compared. For all other characters 
the comparison is of coefficients of variation. 
8 Measured from base of midvein to tip of central lobe. 
8 Measured from tip to tip of the principal lateral lobes. 
4 Width as a percentage of the length, instead of length as a percentage of the width, the value used in the 
paper by Kearney and Wells, cited on p. 2 27. The new leaf index is the reciprocal of the old, multiplied by 
6 Width (in degrees) of the angle formed by the principal lateral veins. 
the midvein to the bottom of the upper 
right hand sinus. A deeply lobed leaf has a high lobe index and vice versa. 
* of the basal cxtensio } 1 of the blade, below a line bisecting the base of the midvein at a right angle 
to the latter, as a percentage of the length of the leaf. 
8 At the point of greatest diameter. 
9 Maximum diameter as a percentage of the length, instead of length as a percentage of the diameter the 
value used in the paper by Kearney ahd Wells, cited on p. 227. The new boll index is the reciprocal of the 
old, multiplied by 10,000. 
The coefficients of variation of the parent progeny, as compared with 
those of the 5-3 bulk, were higher in 8 and lower in 4 of the 12 characters; 
1 Since only 30 plants of the “Pima parent” progeny had leaves in good condition for measurement, the 
leaf characters were determined on only 30 plants in the other two stocks. The boll, fiber, and seed charac¬ 
ters were determmd on all 32 plants of each stock. The leaf characters were measured on selfed progeny 
YiA and the other characters on selfed progeny Y2A. 
