Fig. 4. Dynamic mechanical properties of each type of fibrous silk spun by Argiope argentata (mean ± s.e.m.). For these data only, s.e.m. was calculated using the total number of fibers tested as the sampling unit, rather than individual spiders. Properties for capture spiral were measurable only at high strain. See Table 2 for sample sizes. E', storage modulus; tan , loss tangent; ac, aciniform; cp, capture spiral; mj, major ampullate; mn, minor ampullate; tb, tubuliform.