On Cell-wall Structure as seen in Cotton Hairs. 435 



Sep. 20. * Oct 10. Oct.20. 



Fig. 12. 



Figs. 11 and 12. — From capsules opening on successive days in the daily pickings seines 

 (q.v.) five seeds were taken each day at random, and twenty hairs of similar length 

 from each of these five were arranged with their bases in line. The number of 

 convolutions included in a microscope field of 1"6 mm. was then determined at three 

 loci along the hair, respectively, 5, 15 and 25 mm. from the base. The curves as 

 shown are the three-point means of the original data, each point thus representing 

 the average of 300 hairs. The data are further analysed in fig. 12 in order to 

 discriminate between general fluctuation common to the whole length of the hair, 

 as indicated in fig. 11, and the existence of differential fluctuation in various parts, 

 due to determinations taking place at different times during development. The 

 logarithmic plotting shows that the latter fluctuation is quite marked, though its 

 amplitude is reduced by a half. 



