The rate of cytolysis in osmotically stressed unfertilized sea urchin
eggs was analysed using a version of the Johnson-Mehl-Avrami equation,
and fit with high precision (r2 > 0.90) if the data sets were divided
into two sectors. The slow process was first-order but the Avrami coe
fficient, n, for the initial fast reaction was 7. Suspecting that this
might be a peculiarity of cells which are primed for climactic behavi
our, we examined the process in red cells, whose decay is known to be
of first or lower order at low temperatures if protected from excessiv
e osmotic stress. Human red cells subjected to 'thermal shock', in whi
ch osmotically stressed cells are cooled below +12-degrees-C, show a p
attern almost identical to the stressed sea urchin eggs except that n
of the rapid process exceeded 10. Based on the geometrical implication
s of such a high n, we believe that this phenomenon reflects a stress
failure in the cytoskeleton and has important ramifications in cryopre
servation.