Figure 21. Callinera grandis, schematic drawing of a dorsal view on the central nervous system, based on 3D-reconstruction of 140 aligned 0.5 µm sections.

The central nervous system is composed of neuropil (np, gray), which is surrounded by cell somata (cs, blue). Cephalic nerves (cn) are circularly arranged; the paired proboscidial nerves (pn, yellow) originate from the ventral commissural tract (vct). A dorsal nerve strand (dn) originates from the dorsal commissural tract. The branching esophageal nerves (en) originate from the ventral commissural tract. The lateral medullary cords (mc) originate ventro-caudally in the brain. The letters on the right (a–f) refer to the histological sections in figure 22 .