Detection of Maltose in Tissues of Angiospenns. 163 
removed to cool whereupon it very quickly yielded an abundant crop 
of extremely large sheaves and bundles of osazone crystals. 
Dextrose behaved in very much the same manner, but the 
production of crystals was less rapid and the amount smaller. 
Cane sugar, after being heated for ten minutes, shewed a slight 
lemon-yellow colouration, which had changed to orange-yellow at 
the end of another five minutes in the water-bath. On allowing the 
preparation to cool after having been heated for half-an-hour, Senft 
found that a copious supply of sheaf-like crystal clusters was soon 
yielded, a result which he attributed to the inversion of the cane- 
sugar by the action of the hot reagent, with the production of 
levulose and dextrose. 
He does not appear to have employed maltose at all in this 
portion of his work. Crystals of maltose phenylosazone are, how¬ 
ever, shewn in his figures, illustrating the results subsequently 
obtained with Ginkgo biloba, Daunts Cavota and Elodea canadensis. 
In repeating these experiments with solutions of levulose and 
dextrose of strengths varying from •5% to 10%, while obtaining the 
same general results after heating for half-an-hour at 100°C, I have 
often noticed that levulose shews a preference for the large radiating 
or sheaf-like form of crystal grouping, while dextrose more often 
forms smaller and more spherical aggregates of crystals. With 5% 
or 10% levulose the sheaves of crystals branch repeatedly and rather 
resemble the patterns produced by frost on window panes, a result 
rarely given by dextrose. The actual forms obtained vary with the 
strength of the solutions and may, perhaps, depend also upon other 
factors, but the distinction holds good for moderately weak solutions 
in a general way (Figs. 1 and 2). 
With regard to cane-sugar while stronger solutions do undergo 
a certain amount of inversion after prolonged heating, in the case 
of weaker solutions this inversion appears so small as almost to be 
negligible. Working with solutions of “ Cane sugar,” I found that 
osazone crystals were obtained some time after cooling when a 10% 
solution had been heated for an hour, but that a 5% solution gave no 
crystals during the succeeding two or three days. Subsequently 1 
repeated the experiments with drops of a 5% solution of “ Cane 
sugar, puriss,” After an hour’s heating no crystals had appeared 
at the end of five days, although numerous minute yellow drops of 
liquid had formed. 
After heating for an hour-and-a-half only yellow drops were 
1 L.c., pi. II., figs. 8-11. 
