Study on the Karyotype ofSpalax LeucodonNordm. and S.MicrophthalmusGuld

Abstract
The authors have studied the karyotype of the Spalax leucodon species living in Romania, and they have found that on each side of the Carpathian mountains (North and South) the animals have a different number of chromosomes, i.e. 2n = 56 and 2n = 50. This considerable variation in the number of chromosomes may be due to a Robertsonian process of karyotype evolution which is favoured by the lack of migration possibilities. The study of the karyotype in Spalax microphthalmus has proved that this species has a constant number of chromosomes (2n = 62), no matter of the animals' origin.