“…How ever, the activities of the endocrine organs of small hibernating mammals exhibit more pronounced fluctuations than the non hibernating species [Eisentraut, 1956], Sev eral earlier reports indicate involution of the anterior pituitary, thyroid and the adrenal cortex in hibernating mammals [ConinxGirardet, 1927;Foster and Meyer, 1939;Skowron and Zajaczek, 1947;Kayser, 1950Kayser, , 1961. Further, in hibernating species there is some evidence of hyperactivity of the adrenal and the thyroid in the early spring which appears to be associated with the sea sonal sexual activity [Zalesky, 1934[Zalesky, , 1935Foster, 1934;Kayser, 1950Kayser, , 1961Girodet al, 1967], A detailed statistical analysis of the monthly and the seasonal variations in the body weight, and the dimensional characteristics and the weights of the thy roid, adrenal and the testis, are largely lack ing [McKeever, 1966]. Therefore, the pres- Values given are average mean ( ± SE) of the right and left organ of each animal in the given phase.…”