ABSTRACT
Having established that a crab can retain a visual impression of the positions of contrasting stripes in its visual field for a period of many minutes in the dark with an accuracy of about 
over short periods, it became of immediate interest to know whether other arthropods can do the same. The same technique as in the previous papers (Horridge, 1966a) was therefore applied to the locust as a convenient large insect. The locust is especially appropriate in that we have information on the electrophysiology of the visual system (Horridge, Scholes, Shaw & Tunstall, 1965) and on the optomotor response to moving striped drums (Thorson, 1965). The question is of interest not only for comparative purposes but because for further analysis of some aspects of optokinetic memory an insect is more likely to be of value than a crab as an experimental animal.
