Figure 25. Simple apparatus built with a balloon to represent the eye tube of the right AME, a roll of paper to secure the anterior end of the tube, and attached rubber bands used to model the action of each of the four (1-4) extraocular muscles, as well as the two circular ocular muscles (5, 6). Muscle numbers correspond to those assigned by Land (1969b). By pulling on one or more rubber bands, the likely action of the respective muscles could be observed directly. The action of the circular muscles was more challenging to model, but I was able to simulate their contraction by pulling the ends against a loop in the middle of each band.