Анотація:
A prolonged light day (16-18 hrs) established before the beginning of the spring moult had no essential effect on its time and did not prevent an autumn moult of Sciuvus vulgaris L. With a short (8 hrs) light day the spring moult began at proper time but was prolonged and did not come to an end completely. Neither elevated nor lowered temperature of the environment affects the time and proceeding of spring moult and favour regeneration of hair in sheared spots. The results of the experiments permit one to consider that in the complex mechanism of the seasonal change of the hair coat in Sciurus vulgaris involving endogenic and exogenic factors interacting between themselves an internal physiological rhythm of the organism plays the leading role. Photoperiodism the main exogenic synchronizer of this rhythm is of the secondary importance.