Morphological characteristics of clusters. The average length of filaments in a cluster (Panel A) and the area covered by each cluster (size) (Panel B) were determined and plotted against the calculated density of the cluster. Each cluster is represented separately in Panels A and B. This data was then averaged and summarized in Panel C (area), Panel D (filament length) and Panel E (density). Polymerization products from 25 μM ARA-induced polymerization reactions are presented as white circles and bars; those from 75 μM ARA induction are presented as black circles and bars. Error bars are +/- SEM.