Shows that olfactory cues arising from fecal materials generated by the rat when shocked play an important role in the subsequent arousal of fear. 5 experiments employed 80, 84, 135, 9, and 33 male albino rats. Reliance on olfactory cues applied at both short and longer postconditioning delay periods. With short delay, adrenocortical activity and olfactory cues combined to produce a high level of performance. With longer delay, an increase in cue value of the odor appeared to compensate for a decrease in level of adrenocortical activity. When odor was controlled, the Kamin effect occurred in the retention of acquired fear. (PsycINFO Database Record (c) 2006 APA, all rights reserved)