File:Fig. 3 Billen and Al-Khalifa 2018, longit section venom gland.png

Fig. 3. A. Longitudinal semithin section through venom gland filament in worker with central lumen and sections through end apparatus (black arrowheads). B. Electron micrograph detail of end apparatus in worker. Note abrupt transition (arrowheads) of thick and continuous cuticle in duct cell (DC) into thin and discontinuous cuticle in secretory cell (SC). Small white arrows indicate disrupted epicuticular inner lining. C. Ultrastructure of secretory cell cytoplasm (queen) with granular appearance because of abundant free ribosomes, and with well-developed Golgi apparatus (GA) and mitochondria (M). D. Detail of nerve fibre (NF) wedged in between gland cells (queen). mv: microvilli, N: nucleus.