Variations in the Carbohydrate Content. 123 



(ii.) The pentosans form a larger and larger proportion of the 

 matter insoluble in alcohol as the season advances. 



(iii.) Of the total sugai-, the hexoses form a progressively 

 increasing proportion as the season advances. This point has 

 already been brought forward very clearly by Parkin in the case of 

 the snowdrop (see Table XXXIV). 



FlO 16. Variation in Content of various Carbohydrates in the Leaf of 

 Mangold during 24 hours, Oct. 11—12, 1913 (After Davis, Daish and Sawyer). 



