Abstract: The 3-5 year population cycles of some vole(Microtinae)species are fascinating in that consen-sus concerning their regulating mechanisms are far from being reached.Along with the emerging of more reasonable hypotheses,some outdated,invaled hypotheses, such as the food,nutrition-al,and multi-factorial hypatheses, have been abandoned for their apparent violation of some sim-ple ecological principles.Unfortunately,we are aware that some investigators in China are mak-ing their attempts to support,or even test.the above-listed hypotheses,using experimental re-sults from non-cyclic vole populations.We present here eight.some interrelated,reasoning at-tempting to demonstrate the invalidity of these hypotheses;and those devoted students in popula-tion ecology are expected to be concentrated in the searching of internal──mainly bebavioral and physiological──factors which regulate vole number in their studies of vole population regu-lation.

Key words: Cd^2+, Procambarus clarkii, antioxidative enzyme, antioxidation substance.