83 
it is very probable that the gain corresponds to the West and 
the loss to the East. 
But} apart from this insufficiently registered observation, it 
clearly appears from the above that the leaves of a tree or 
shrub produce very different quantities of food according as 
they occupy an Eastern or a Western position. Between the 
end of February and the end of September the sun at Buiten- 
zorg has a Northern declination and proceeds accordingly from 
Kast through North to West, but in the other months the 
reverse takes place, the leaves on the Southern side being 
then placed in more favourable circumstances for assimilation 
than the Northern ones. 
It must be a necessary consequence of the leaves being 
unequally stored with organic matter during the daytime, that 
they also show a difference of losses at night. This loss was 
determined in leaves of which the leaflets of one side were 
cut off at 5.30 p. m., whereas those of the other side were 
taken off the next morning at 6. This experiment which was 
repeated a couple of days after, showed losses of respectively 
0.14 gr. and 0.33 gr. an hour. 
These losses are pretty well covered by the production 
mentioned before. For if we assume an average loss of 0.23 
gr. an hour and the night is supposed to last 12 hours, the 
Whole loss amounts to 2.76 gr. If the actual production is 
calculated from the above figures + 0.10, + 0.32, +0.44 and 
— 0.09, the average is found to be 0.19, which multiplied 
into the number of day-hours, makes 2.28 gr. It should be 
noted however that the production has been rated a little too 
low, and the loss a little too high, because the sun on the 
I of June rises at a quarter to six and sets at 64 after a 
very short twilight. 
Delima sarmentosa is also a pretty tall shrub with long 
branches , of which the extremities often taper to almost leafless 
tendrils, which either seize some prop or hang down to the 
ground. This plant has tough leaves with strongly projecting 
midrib and veins , presenting every facility for cutting out 
