MAGNETIC RESPONSE OF AN ORGANISM AND ITS SOLAR RELATIONSHIPS

¹ Departments of Biological Sciences, Northwestern University, Indiana State Teachers College, and Sweet Briar College, and The Marine Biological Laboratory, Woods Hole, Mass.

1. The orientation of snails in a constant, symmetrical field was studied over a two-month period, June 28 through August 29, 1959, at various hours of the day between 5 AM and 9 PM.

2. The orientation of snails in the earth's natural magnetic field was compared throughout the study with the orientation of snails subjected to a 9- to 10-fold increase in field strength, with fields both parallel and at right angles to the earth's natural field.

3. A daily rhythm in the direction and average amount of turning was found in the snails; the mean paths of those in the two (N-S; E-W) experimentally augmented magnetic fields were statistically significantly to the left of the controls, particularly between the hours 7 AM through 9 PM.

4. The mean amount of turning, whether clockwise or counterclockwise (klinokinesis), in the experimental magnetic field was also increased significantly over that of controls in solely the earth's field, and similarly exhibited a daily rhythm.

5. Certain similarities between the orientational responses to the magnetic fields and earlier described exogenous metabolic fluctuations in constant conditions, suggest a relationship between them.

6. Evidence is advanced supporting the hypothesis that the orientation of snails normally includes a true response to the earth's magnetic field.