than at 24 h. This is supported by the image length
values for the control group, which were significantly
greater at 24 h than at 1 and 2 h. At both MMS concentrations
(2 and 4×10−5 M), image length, damage index
and damage frequency were significantly greater
at all exposure times in relation to the control for that
exposure time, with the exception of the group exposed
to 2×10−5MMMS for 1 h. After 24 h exposure
to 2 × 10−5M MMS the damage index and damage
frequency values were significantly higher than at 1 h,
while at 2 h not only were damage index and damage
frequency values significantly lower than at 24 h but
the image length values were also significantly lower.
For the 6 h group, however, the only significant relationship
with the 24 h group was that the damage index
was significantly lower than at 24 h. The image length
and damage index at 6 h for the 2 × 10−5M MMS