102 : ^TH^^DE^EWMENT OF RAW COTTON 



places the cause of out-turn variations in the very last 

 stage where one would ever think of looking for it 

 Th Cause of name ty> ^ n ^ ne pen flower ! At the same 



Out-turn time it has the merit of explaining every 

 Fluctuations, peculiarity which ginning out-turn displays. 



If we take the curve showing daily variations in the 

 average lint weight per seed, and calculate the weight 

 of lint which would be borne each day if the seeds were 

 all of the same weight e.g., 0-1 gramme, we obtain the 

 ginning out-turn expressed in a somewhat different form, 

 with the seed as the foundation unit. If we now take 

 this curve of standardized lint weight, and compare it 

 with the curve for lint length, we find that they are closely 

 similar when a shift of about a fortnight is made, so 

 that conditions of the environment which are affecting 

 the length of the lint in a fifteen-day boll are brought 

 into line with their simultaneous action on a boll which 

 is newly set. 



There is only one way in which this effect can be ac- 

 counted for namely, by changing the number of epi- 

 dermal cells which sprout into hairs (Fig. 11, C, a). To 

 confirm this conclusion by direct observation would 

 require the counting of all the hairs on a large number of 

 seeds, a task which is humanly impossible by any direct 

 method;* an indirect method which the author attempted 

 will be mentioned below. ^ 



* While this book was in the printer's hands an article by 

 Mr. Leake appeared in the Journal of Genetics (1914), dealing 

 with ginning out-turn in the Indian cottons. By infinite patience 

 aided by the shorter and coarser nature of the Indian lint 

 he has achieved the " impossible," and shows that the differences 



