In an attempt to confirm E'awe-Spurrier 's original report of blood borne hibernation induction trigger (HIT), an experiment was designed on a Chinese seasonal hibernator, Citellus dauricus.26 animals were divided into 3 groups for transfusion, group H (10 squirrels) ,was transfused with preserved sera from deeply hibernating animals in winter; group A (9 squirrels), with preserved sera from active animals in spring; and group S (7 squirrels), with 0.9% saline. After transfusions, the animals were kept in i...