75 
able first to get rid of the chloral which extracted too much 
water from the grains of amylum. 
In far the most cases a macroscopic examination of the blue 
coloured leaves was quite sufficient to afford an idea of the 
distribution of the amylum in their tissues; still whenever a 
brown colour prevented its discovery and in other cases of 
uncertainty the microscope was applied. 
As regards the selection of plants, different species were used , 
which after an accidental collection proved the best; besides 
also certain cultivated plants, for instance Tea, Coca, Theo- 
broma &c¢ were examined. The short duration of my stay in 
Java (4} months) during which also some other phenomena 
were studied, prevented me from extending my researches to 
various plants, which I should have liked to watch in the 
same way. The so called Nasturtium (Tropaeolum majus) for 
instance which I should have wished to test with a view to 
comparative examination after my return to Europe, looks so 
poorly under the tropical heat, that I was compelled to give 
up my intention. 
As may be gathered from what follows, the leaves were 
collected from 5.45 a. m. till 5.30 p. m.; at times when I 
happened to be prevented from going to the garden, Mr. J. 
J. Smith jun. was kind enough to perform the needful opera- 
tions. Dr. P. van Romburgh obliged me by immersing at fixed 
times some leaves into alcohol, from plants grown in the cul- 
ture-garden, a part of the Botanical Garden properly so called , 
and under his special management. 
Quantity of amylum contained in the leaves im the early morning. 
In order to give a clear notion of the relative quantity of 
amylum found at sunrise or a little after, I subjoin a tabular 
statement, in which some details are registered. 
