to three per animal. The frequency of mosaics showed seasonal variation. In the population of the Ussuriiskii reserve, a sharp increase in the frequency of animals with a stable karyotype was detected in autumn, at the phase of increased numbers. The variation for mosaicism was suggested to correlate with the population numbers in mice and to indicate the genetic differences between generations of the population.introduced into the capillaries during the exposure of the capillaries to an outer environment and then a loss of the PCF is increased. Furthermore, several air voids present on a cross-section of the PCF induces a large refractive index difference between the PCF and a normal silica optical fiber, which renders the splicing between the PCF and the silica optical fiber difficult.