~16-
time is one-eighth thet of the pretest level;
is an increase in activity.
subsequently there
Since both the total activity and
the long-lived activity increased by approximately equivalent
amounts, the increase must be due to an
increased net rate of
uptake, reflecting a change in the physiology of the crab or 4
change in the conditions in the environment,
availability of,
leading to a greater
in this case, Csl37 to the crab.
The latter
possibility is the more eastly explained by the observations.
The same pattern of decrease in activity followed by a rise
is evident in the gut and liver of the crab, the leaves of the
shruts, Scaevole and Messerschmidia, and the muscle of the field
rat, Rattus exulans, from Janet (Engebi) Island, which is also in
the northern part of Eniwetok Atoll.+9 During the first 200 days
(May - November, 1954)
rainfall at Eniwetok
averaged about 4
incnes per month while for the following 150 days
(December -
April) the average monthly rainfall was about 0.3 inches (Fig.7).
Since individual variation in the level of activity is great
there would be little reason to accept the validity of the correlation were it not repeated in the plants and in rat
muscle,
which are also high in Csli37 content, (56% of the total activity
in the latter).
It appears likely, therefore, that the changes
in activity in the crab and rat muscle reflect some underlying
mechanism associated with rainfall which is responsible for
changes in the levels of activity itn the plants.
There could be one or several factors involved in the association with
rainfall
including,
for example,
such things
gor
as