112 THE DEVELOPMENT OF RAW COTTON 



DAILY PICKINGS OF 1913 (Fio. 15). 



The series of data accumulated under this title were 

 derived from an " observation row " of about 130 plants 

 growing under field crop conditions at Giza, on rich deep 

 soil, severely attacked by both ordinary boll-worm and 

 pink boll-worm, but otherwise typical of excellent culti- 

 vation, and setting a crop of bolls which in the absence 

 of this exceptionally bad attack of boll- worm would have 

 weighed out at 700 pounds of lint to the acre. 



The part of the field containing this group was carefully 

 watched every day of the season, and the general health 

 of the plants was kept as uniform as it could be, under 

 the limitations of field cultivation. Any fluctuation 

 shown in the cotton ripened in this experiment will, 

 therefore, be less, if anything, than an ordinary field 

 would show when cultivated with the same pure strain. 



The strain employed was the same as in the previous 

 series, and comparison between the two results brings 

 out some points of interest, especially with regard to the 

 senescence or self-poisoning induced in the previous 

 experiment by withholding water early in the season. 



The data thus obtained are directly "practical." 

 The successive days are dated by the opening of the boll, 

 or picking, and not by marking the flowers, while the 

 strength was determined by " impact testing " of bunches 

 of lint, and not by breaking single fibres. 



Although the series embraces ninety consecutive days, 

 the measurement of length on 500 seeds, and the count- 

 ing of about 4,000 fibres one by one, the results can be 

 summarized in a very few lines : 



