Variations in the Carbohydrate Content. 1 2 1 



and sucrose in two samples collected at the same time, in which the 

 hexosfe determinations in the two cases differ by 6%. The only 

 information this }>ives us is that there is possibly a considerable 

 error due to the variability of different samples, but two samples 

 alone can give us no idea whatever of the actual magnitude of the 

 probable error, which Davis and his co-workers have not determined. 

 It is therefore misleading to give these two analyses under the sub- 

 heading " Error of Sampling." 



In Fig. 15 are summarised the results of analyses of leaves in 

 the second period. Here the hexoses are in excess of the sucrose 

 Both curves show synchronising maxima at 2 p.m., 6 p.m. and 2 a.m. 

 Whether these maxima have any meaning, or whether they are 

 merely the result of differences in sampling, it is impossible to say. 

 The fact that the hexoses and sucrose always show unusually high 



(6% 



6 Su-t\- 



Fig. 15. Variation in Content of various Carbohydrates in the Leaf of 

 Mangold during 24 hours, Sept. 10—11, 1912 (After Davis, Daish and Sawyer). 



lO 



