root, pandanus, spinach, and Morinda.
The algae were collected
both in the shallow water near shore and in the deeper water of
the lagoon, usually in the vicinity of the fish-collecting
stations.
Sample values are given in Appendix Tables IV, V, VI and VII.
From these tables it can be seen that the activity varies widely
even within semples of the same kind.
In January, for example,
the pulp from one papaya had an activity of 8.6 x 107" uc/g (wet),
the highest level found in any edible plant portion on that date,
while the pulp from a second papaya specimen had an activity
of 1.3 x 10°! uc/g (wet).
In both edible and non-edible plants the specific activity
was higher in the leaves than in the fruit,
erally being two to eightfold.
the difference gen-
Much of the activity in the
March 1954 plant samples was probably due to surface contamination.
High counts in the internal portions of stems, however,
indicated rapid uptake of fission products by absorption through
the root systems.
Later collections also indicate uptake of
fission product material within the leaf tissue.
For example,
leaf buds formed after the initial fallout contain as much
activity as do older leaves, and washing removes very little of
the activity.
In the earliest coliections the bark of shrubs and trees
and the epidermis of edible plant ports contained from 14 to 40
times more activity than the internal parts.
lections, however,
In the later col-
tujis ratio wes always less than two.
It is
not definitely known, however, whether differential uptake or
Ty
pris.
,
2