SYMMETRICAL PATTERN IN M-1 AND M-3 MOLARS IN CLETHRIONOMYS-GLAREOLUS

We examined the occurrence of the same pattern of M-1, and M-3 on both halfs of a jaw in samples from seven localities of no more than 100 k m apart (in total 4,451 ind.) of the bank vole (Clethrionomys glareolu s) aged 1 to 5 months. More than 50% of individuals did not have the s ame (symmetric) pattern on both sides of the same jaw. The symmetric c omplex pattern of M, in mandibles (ranging from 26.28 to 39.6%) and th e symmetric simplex pattern of M-3 in upper jaw (ranging from 28.3 to 44.0%) dominated in all populations, but there were no statistically s ignificant differences in this respect. Before refuting the Importance of this type of study for the systematics of the bank vole, more geog raphically distant populations ought to be compared.