Fadenwurm. Nematoden auf Agar und Darstellung ihrer Spur. 1. Ungerichtete Fortbewegung ohne CO[2]. 2. Gerichtete Fortbewegung im CO[2]-Gradienten. 3. Verhalten an der CO[2]-Quelle. 4. Verhalten nach Entfernen der CO[2]-Quelle. Schräglichtbeleuchtung. Normalfrequenz und geringe Zeitraffung.

Ditylenchus dipsaci moves at random on an agar surface. Locomotion in nematodes being by undulatory propulsion the tracks left behind correspond to this mode of motion. As no CO[2]-source is present in this phase, forward movement is aimless. After the introduction of CO[2] by means of glass capillary tube the nematodes orient in the gradient formed and move to the source. After removing the CO[2]-emitting capillary tube the nematodes react by turning and twisting and by movements back and forth. Normale frequences and lesser time-lapse.