Abstract
[long dash]Experimental evidence is presented which indicates that a living organism, Dugesia dorotocephala, is able to relate the vector directions of a horizontal pattern of illumination to the concurrent, ambient, 360* geographic grid of such a subtle pervasive field at that of geomagnetism. The spatial association which is formed as "remembered" for at least many minutes. Such a demonstrable capacity to "code" an ambient pattern of light on a subtle geographic or spatial grid renders it probable that living systems are able, normally, to "code" ambient temporal patterns of illumination or to other obvious factors on the 360[degree] temporal grids of subtle geophysical variations related to the solar day, the lunar day, and the year. It is postulated that this newly discovered capacity may be an essential component of the so-called biological clocks and compasses.