498 ANNUAL REPORT SMITHSONIAN INSTITUTION, 19 60 



are following. For cotton, as in all research, the goals lie always 

 farther ahead, with still greater benefits yet to be gained. 



ACKNOWLEDGMENTS 



All photographs and photomicrograplis used in this article origi- 

 nated in the Cotton Division, formerly of the old Bureau of Agricul- 

 tural Economics and now of the Agricultural Marketing Service, U.S. 

 Department of Agriculture. 



The cotton liber cross sections pictured in plates 3 and 4, resulting 

 from the application of exceptional skill and technique on the part 

 of their maker, were prepared by T. L. W. Bailey, Jr., one of the first 

 recruits in Dr. "Webb's original cotton fiber research program. 



Table 1. — Cotton fiber cross-sectional data for S figures in plate 3 



1. Fine fiber, Sea Island cotton: 



Average total area 80.62 square microns 



Average wall thickness 2.26 microns 



Average ratio axes: major/minor 2.80 



Average fiber diameter 14.28X6.79 microns 



Approximate wt./in 1.82 micrograms 



2. Fine fiber, American upland cotton: 



Average total area 127.50 square microns 



Average wall thickness 2.86 microns 



Average ratio axes : major/minor 2.80 



Average fiber diameter . 18.19X7.15 microns 



Approximate wt./in 3.44 micrograms 



3. Medium fiber, American upland cottons: 



Average total area 148.83 square microns 



Average wall thickness ,-- 2.68 microns 



Average ratio axes: major/minor 3.37 



Average fiber diameter 22.03 X 6.75 microns 



Approximate wt./in 4.20 micrograms 



Table 2, — Cotton fiber cross-sectional data for 3 figures in -plate 4 



1. Medium fiber, American upland cotton: 



Average total area 178.67 square microns 



Average wall thickness 3.36 microns 



Average ratio axes: major/minor 3.29 



Average fiber diameter 22.91 X7.S9 microns 



Approximate wt./in 5.30 micrograms 



2. Coarse fiber, American upland cotton: 



Average total area 252.86 square microns 



Average wall thickness 4.30 microns 



Average ratio axes: major/minor 2.82 



Average fiber diameter 25.60 X 9.85 microns 



Approximate wt./in 7.92 micrograms 



3. Very coarse, Asian cotton: 



Average total area 606.02 square microns 



Average wall thickness 9.33 microns 



Average ratio axes: major/minor 1.52 



Average fiber diameter 20.42X20.50 microns 



Approximate ^\i;./in 20.30 micrograms 



