86 THE COTTON PLANT IN EGYPT chap. 



that the " ginning out-turn" is highest in the strong lints. 

 This ranged from 48 to 111 ; mean at 75 about. 



strength. Mean Out-turn. 



Weak 69-90 



Medium 72-96 



Strong 74-67 



The last result gives a partial clue to the preference for 

 high " out-turn " which the buyer — indepeindently of the 

 grower — displays. A few notes on this matter should be 

 made. 



Ginning out-turn. — The out-turn of lint from seed 

 cotton at the gin is expressed in Egypt as rotls of lint per 

 315 rotls of seed-cotton. The extreme means recorded 

 for a whole factory throughout a season are 113"3 (Abbassi, 

 Qalioubia, 1899) and 88-0 (Ashmouni, Sharkia, 1888). 

 Variations in this figure occur from place to place, but 

 when the mean out-turns of large ginning factories are 

 considered, we find "that the variation-graphs for a number 

 of years are closely similar in different places. ^^ Thus 1903 

 showed a sudden rise of out-turn almost everywhere in 

 Egypt. 



These variations are as yet inexplicable. Wide-sown 

 plants give much lower out-turns than those which are sown 

 in field crop,* and nitrogenous manures in field crop also 

 depress the out-turn, through increase in the seed-weight.t 

 The variation is due, of course, to imperfect correlation of 

 lint- weight with seed- weight.^- This correlation had a 

 value of r = 0"810±0'035 in a set of forty-five commercial 

 samples of one variety examined by the author. It has 

 been shown by Mr. J. I. Craig \ that there has been also a 

 slight correlation between mean out-turn and the total 

 Egyptian crop in any given year; r = 0"3899±0'182 for 

 fourteen years. 



The study of variations in ginning out-turn is thus 

 dissected into separate studies of fluctuation in lint-weight 

 and in seed- weight. 



* E.g. Fig. 50. "Varieties." ' f Hughes, 3. ■ J Craig, 3. 



