ence between the two groups of islands may
be drift food brought to downcurrent beaches
and not to upcurrent beaches, Data on
plankton distribution in and around the atoll
(Johnson 1954) suggest that most production
occurs within the lagoon, and that the surrounding ocean is relatively devoid ofplankton compared to densities within, Surface
water moves from east to west through the
lagoon continuously (Mao and Yoshida
1955), and lagoon-produced surface plankton
must be carried with it to the downstream
(western) islands. If this is actually the case,
the western islands would have a richer surface plankton supply, barring substantial
surface eddies at the eastern edge.
The above possibilities led to the formulation ofthis test ofthe effects of food abundance on egg production to examine the
possibility that an enriched food supply
would produce an elevated percentage of
ovigerous females. Egg number per female
was not included in the test because that
would have involved sacrificing the female,
and sampling without replacement would
have depleted the populations significantly.
The results displayed in Figure 3 illustrate