37 
of this gas loaded with moisture. Of course, the opposite change in the 
volume of this included air would take place as the leaf cools. 
It was impossible for me to make observations of any great value on 
the influence of the wind, because I could not regulate or measure its 
velocity. With a good subject, the concomitant use of the cobalt test 
and the weighing method should make it possible accurately to analyse 
the wind’s influence, showing how much is due to mechanical agitation 
and how much to the constant change of the air outside. But no work 
on the coconut is sufficiently accurate and reliable for such an analysis. 
As was to be expected, the wind made a much greater difference in the 
transpiration of the leaves which were exposed to the greatest illumination 
than it did in that of the shaded ones. Thus, in one instance, the transpi- 
ration in direct sunshine was four times as great in a wind I estimated to 
be at 5 miles an hour as it was in a calm; but the increase was usually not 
more than 100 per cent. In the shade, a wind of this velocity added less 
than 50 per cent to the transpiration. 1 was unable to cut off the wind 
from a shaded plant without further interference with its illumination. 
Any estimate of the total water transpired by entire trees can not be 
more than a rough approximation, because, aside from all possible inac- 
curacies in the observations on individual pinne, different days and 
seasons are unlike; and different neighboring trees, as well as different 
parts of the same individual, interfere with each other’s transpiration. 
For these reasons any estimate based on observations made entirely in 
direct light must be too high. As already stated, some calculations 
obtained in this way are as high as 75 liters per diem. In the experiment 
from which the estimate of 28 liters was obtained the pinne were under 
as normal conditions as possible, taking their share of shading with the 
other pinnx of the tree and being under check by observations on pinne 
in the natural position. The day was bright, but was not quite cloudless, 
and not especially warm. 
At the rate of 28 liters per diem the annual transpiration is 10,220 
liters. In this volume of water the plant takes up the mineral food to 
be used in its permanent growth and enough more to cover the annual 
loss in the nuts and cast leaves. The amount of mineral food perma- 
nently bound up in the growth of the stem and roots can not be very 
considerable, and that in the roots which die is already in a place to be 
absorbed again. ‘The average dry weight of a fallen leaf may roughly 
be put at 3 kilograms, of which 8.5 per cent is ash and nitrogen. Allow- 
ing a fall of 16 leaves per annum, the loss of matter taken up in solution 
by the roots is 4,080 grams. In each nut the tree loses ash as follows: 
Grams. 
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