86 
inside the pseudo-vein blue 
upper half blue 
: lower half light blue 
No difference between outside and inside. Upper © 
3 of the leaf fairly dark blue, lower + much 
lighter blue : 
f 3} p. m. } The whole leaf uniformly fairly dark blue 
The leaf undoubtedly lighter blue than inf 
The midrib blue and for this reason slightly 
shaded off from the blade. At the base and— 
here and there near the margin the colour & 
somewhat darker. 
The leaf of Coca consequently begins with losing colour, 
though the conditions for assimilation were very favourable. 
Not till 10; a. m, the excretion of organic matter is surpassed 
by the accretion in the shape of amylum. | 
For Delima I may refer the reader to the list of leaves which 
still contain amylum in the early morning. From a comparisol 
of the colour reaction taken in connection with the hours and 
the condition of the sky, it appears that the influence of the 
light consists in this that leaves which are most exposed to it, 
contain the smallest quantity of amylum. Nor can we draw 
any other inference as regards the two kinds of Tea, also 1 
ferred to in the list. In Thea assamica the difference of colou 
at 9.49 a. m. and about 6.30 a. m. points to a quickened — 
motion of assimilation products after sunrise in the directioD 
of the midrib. This observation may be of some use in deter : 
mining the best time for gathering the tea-lives. If namely ¥ 
is the tea-grower’s object to gather in leaves containing the 
least possible proportion of matter immaterial for the flavol 
of his article, it will be for his interest to fix the gatheriNg 
in of the tea-leaves, for which the usual hour in Java is 9 
a. m., at an hour or so later. 
A few observations on Delima finally deserve attention, vie 
that leaves gathered at 4 p. m. on a rainy afternoon became 
dark blue, whereas on bright days at the same hour they : 
ei eindon | outside , fs 
e 2p. m. 
g 5.50 p. m. 
(one day after) 
