Fig. 4

Granules secreted from pleuropodia of S. gregaria resemble ecdysial droplets. Release of ecdysial droplets by embryonic epidermis on a hind leg during the first (a) and the second (b) embryonic moult, on day 9 and day 12, respectively. (c) Ecdysial droplet secreted during the second embryonic moult at higher magnification and (d) granules secreted from pleuropodia at the same developmental stage. The pleuropodial granules are typically larger, less compact and with non-homogeneous electron density. EC1, EC2, the first and second embryonic cuticles; ed, ecdysial droplets; mv, microvilli; pg, granules secreted from the pleuropodia; PLP, pleuropodium; sp, “spot” of a different electron-density in the pleuropodial granules. Scale bars: in (a) and (b), 2 μm; in (c) for (c) and (d), 500 nm