measure under ambient light was less than half of that in darkness.
The clear peak of activity close to midnight under ambient light
further underlined the limiting effect of light on surface activity.In
the darkened treatment ,the dew-worms became highly active
immediately , remained so through out the night ,and there was no
evidence for differences in this pattern among dew-worm origins.
This shows that the dew-worms were mainly responding to the
prevailing light environment and that activity rhythms as a
consequence of their different longitudinal origins did not decisively control their soil surface activity.