376 Carbolii/dratcn of the Leaf of llic l\tlalo 



appears in considerable excess except just about sunrise (4 a.m.) when 

 the whole of the very small amount of hexose present (0-1 5 per cent.) 

 appears as dextrose not laevulose, and a positive rotation of + 0-015 

 remains unaccounted for. A somewhat similar abnormaUty was found 

 just before sunrise in the case of the mangold leaves, Series I ; whereas 

 during the greater part of the 24 hours dextrose appeared to be in excess 

 (see Table I, Paper II, p. 332, arabiuose values) in the mangold leaf, 

 at 4 a.m., when the total hexose was exceedingly small (0-2 per cent.), 

 laevulose suddenly appeared to predominate; at the same time, the 



Day Night 



6am 8 10 12Noon2PM. 4 6 8 10 12N.ghl2A,M 4 



Fig. 3. Potato leaves. JiJy 16-17, 1914, dextrose and laevulose (apparent). 

 (Pentose as xylose.) 



polarisation results for cane sugar, which in general throughout the 

 day were higher than the reduction values, suddenly became lower. 

 But 2 hours later, at 6 a.m., tiie values were again much higher. The 

 following data illustrate this: 



Mangold Leaves. Series I. 



4 a.m. 

 6 a.m. 



D% 

 0-29 

 000 

 0-73 



008 

 0-20 

 0-00 



August 2(5th-27th, 1913. 



D 



L A* in saccharose values 

 3-62 + 7-3 



- 29-2 



» +42-6 



Sunrise = .5. .5 a.m 

 * A = difference between values found for saccharose by polarisation and by reduction. 



