On the use of assymetric paired organs as indicators of population peculiarities of the European bank vole ( Myodes glareolus Schreber), inhabiting Tver region

Six population of the European Bank Vole from Tver Region have been used as a sample material for understanding the significance of the asymmetry of the paired organs, such as kidneys and adrenal glands, as characteristics of morpho-physiological peculiarities of populations as well as the indicators of the environmental conditions. Certain restrictions for the use of the mentioned organs as indicators due to the patterned asymmetry are existing. Kidneys' asymmetry is better for catching the fluctuating asymmetry. Asymmetry of the adrenal glands is useful in the evaluation of the morpho-physiological peculiarities of certain populations. The populations studied have been split apart on the base of the asymmetry of the adrenal glands. They differ in habitats; the first group inhabits the Upper-Volga Province, the second - Valdai and Smolensk-Moscow Province.