Surveyor v landing: the effect of slope on bearing capacity.

Differences in latency to the air from the same rat when stressed and unstressed were comparable to differences found when one rat was stressed and another unstressed. This observation would also suggest that the discriminable odor did not derive from a chronic stress state, but arose immediately from a given stressing. Neither can the discrimination be reasonably attributed to greater familiarity with odors of the unstressed rats as a group. Air sampled from unstressed animals not previously used did not produce the long latencies associated with S-air. The possibility that a cue might derive from the living cages from which the stimulus air was sampled, was tested by placing Uand Sstimulus rats in completely new cages ^ for 30 of the 100 test trials. Results were indistinguishable from those obtained when air samples were taken from the living cages. The major finding of this paper that rats can respond differentially to odors of stressed and unstressed rats suggests the need for instituting experimental controls in those studies in which odor from a stressed animal might affect behavior of nearby animals. Previously such controls were not thought necessary. We are presently seeking to locate -the odor source in the animal's body to assist us in determining whether the material has pheromonal activity and in its eventual chemical analysis. JoHN G. VALENTA MARILYN K. RIGBY Departments of Chemistry and Psychology, Rockhurst College, Kansas City, Missouri 64110