THE CARBOHYDRATES OF THE ANGIOSPERM LEAF 15 



inulase were also found in these storage organs, in presence 

 of their respective substrates, but in smaller quantities than 

 was invertase. 



TABLE VI. 



ENZYMES OF Beta vulgaris. 



Robertson, Irvine, and Dobson, obtained from 4 to 6 per 

 cent, of sucrose by treating invert sugar with a turbid 

 liquid or sludge prepared by straining leaves macerated 

 with water through fine muslin and precipitating with 

 alcohol. The change was studied with the polarimeter, and 

 after inversion with acid the original rotatory power was 

 recovered; thus there can be little doubt that sucrose was 

 produced. Hudson (1914) has, however, shown that pure 

 invertase has absolutely no synthetic action. 



From the results of his analyses of beet leaves picked 

 before sunrise and late in the afternoon, Girard (1883, 1884) 

 concluded that sucrose was the principal sugar to be directly 

 formed in sunlight, and that it alone was stored in the root. 

 From his table quoted below it may be seen that, while the 

 hexoses remain fairly constant, sucrose increases to a marked 

 degree upon insolation. 



It may be mentioned that in a recent paper Colin (1914) 

 controverts Girard's statement that sucrose only is found in 

 the beetroot, for he has found in it a small quantity of a 

 reducing sugar, which decreases in amount as the plant 

 grows older. It may possibly be that in some varieties of 



