The purpose of an investigation by Alahuhta et al. was to evaluate
the influence of extradural block (a type of anesthesia) for elective caesarean
section on various maternal and fetal variables.  The subjects were 8
healthy pregnant women.  Measurements of maternal diastolic arterial pressure
were taken at two stages during each woman's caesarean procedure.


The two variables are:
     stage1 -- diastolic blood pressure at stage 1
     stage2 -- diastolic blood pressure at stage 2