Figure 17-5. Polar Wedge Histograms of Instantaneous Direction of 
Travel with Respect to the Filter Reference Frame for D. Pulex. 
NOTE: (A) in polarized light (evaluated for the path plotted in Figure 17-1) 
and (B) in unpolarized light. The percent of sample within each angular 
category is indicated on the radius. The dashed circles denote expectation for a 
circular uniform distribution. 
