Figure 2.

Third cleavage in an AV-parallel magnetic field. Top (a, c, e, g, and i) and side (b, d, f, h, and j) views of eight-cell embryos from an AV-parallel field, showing the classes of third cleavage reorientation. For the side views, the embryo in the top view was rotated with the animal pole away from the viewer. The numbers of horizontal cleavages depicted are four (normal; a and b), three (c and d), two (e and f), one (g and h), and zero (i and j). (k) The average number of horizontal third cleavages per embryo as a function of field strength.