To compare the patterns of overnight activity of the three
earthworm origins,each night was divided into three successive
two-hour periods and the variation of the original dichotomic
activity observations was modelled with the same explanatory
variables as above.The response variable was assumed to follow a
binomial distribution and a logit-link function was used in the
analysis.Data for the three periods were analysed separately.The
results were expressed as odds ratios(OR;value 1 indicating no
difference)and their 95% confidence intervals(95%CI).The confidence
intervals were related to the P-values such that the odds
ratios were not statistically significant if the confidence interval
contained 1.The start and end times of activity were analysed
using regression analysis of survival data based on the Cox proportional
hazards model.Analysis of mating frequency was also
undertaken and used a binomial model with the occurrence of
mating in a tube(0 vs.1 for each tube per night)as a response
variable,and the light treatment,earthworm origin,and their
interaction as fixed explanatory variables and tube as a random
effect.