Figure 13

Formation of space holders (asterisk) and longer lengths of air sac as a result of fusion and cuticularization of the former cell fragments, now cuticle- enclosed components (CuC) of the air sac. First instar, Centruroides gracilis. TEM. Small dense granules (G, 20-30 nm dia.) from the adjacent aligned cells (e.g., Fig. 12) appear to fuse with the developing cuticular wall (Cu), giving it a granular texture (GT) at some sites where the wall is forming. This process appears to be similar to cuticularization observed with SEM [1, 27]. The fused cuticle from adjacent components (CuC) may continue as space holders (bridging trabeculae) evident in more advanced air sacs (e.g., Figs. 15, 16, 17). Scale, 200 nm.