1. R. Wehner, J. comp. Physiol.77, 256 (1972); T. S. Collett and M. F. Land, J. comp. Physiol.100, 59 (1975).
2. The literature on homing by use of landmark memories is summarized in R. Wehner, Handbook of Sensory Physiology, vol. VII/6B, Vision in Invertebrates. Springer, Berlin, Heidelberg, New York, in press.
3. The experiments described here were performed near Maharès, Tunisia (34.58° N, 10.50° E) during summer 1976. They are only part of a larger project on ant homing by the use of landmark cues (‘piloting’) (R. Wehner et al., in preparation).
4. G. van Beusekom, Behaviour1, 195 (1948); A.M. Anderson, J. comp. Physiol.114, 335 (1977).
5. The zero-point is defined as that point within the testing area that marks the position of the nest in the training area.