2 i8 Ingvar Jorgensen and Walter Stiles. 
From these results Brown and Morris conclude that cane 
sugar is the first sugar formed in the laaf and that this functions as 
a temporary reserve which accumulates during active assimilation. 
When the concentration of cane sugar reaches a certain amount, 
any excess of sucrose is converted into starch in the chloroplast. 
The cane sugar, on being translocated from the leaf, is inverted into 
glucose and fructose, while the starch is hydrolysed and translocated 
as maltose. That it is not hexoses that are the first sugars formed 
in the assimilatory process is indicated by the fact that after 
assimilating all day, leaves still attached to the plant contain no 
glucose and very little fructose. The cane sugar, on the other hand, 
has remained almost constant while starch and maltose have both 
decreased. In the case of the cut insolated leaves it is supposed 
that translocation is to all intents stopped. Under these circum¬ 
stances the cane sugar and starch both increase greatly, but the 
glucose very little. 
The results given in Table XXXI indicate that in the dark 
the cane sugar and starch both decrease in amount, while the 
glucose and fructose have both increased in amount. As presumably 
the sucrose is hydrolysed into equal quantities of glucose and 
fructose, and the latter appears much in excess of the former, 
Brown and Morris conclude that glucose is largely used for 
respiration in the leaf. 
However, from what we have already said on the reliability of 
the measurements of glucose and fructose, it is extremely doubtful 
whether the recorded values of glucose and fructose have any 
meaning. Moreover, Davis and Sawyer (1916) have been unable 
to find maltose in Trcpceolum innjus and they conclude that the 
maltose found by Brown and Morris in their extracts resulted from 
the degradation of starch by diastatic enzymes after maltase in the 
leaf had been destroyed. 
2. Snowdrop (Galanthus nivalis, L) (Parkin). 
The snowdrop possesses the very usual monocotyledonous 
characteristic of not forming starch in the leaves. Hence 
as already indicated, the analysis of sugars is simplified. 
Parkin’s results were obtained from observations made over a 
number of years. In most cases only the values of sucrose and 
hexose are given, no attempt being made, except for a special 
purpose, of distinguishing between the hexoses. Parkin’s results 
are the most clearly stated of all the accounts we have of leaf 
carbohydrates and it is possible from the numbers he gives, to 
