Fig. 1. Photograph (A) and line drawing (B) of the rear aspect of the head capsule of Calliphora vicina. Because the ends of the two optical fibres almost touch the lateral ocelli, their light outputs (blue circles in A) do not overlap. The cuticle of the posterior face of the head capsule is cut away to expose the right-hand lobula plate, and the midbrain cavity, in which the ocellar nerve connects the ocellar neuropil with the brain. Scale bar, 500 µm. CEye, compound eye; LLOc, left lateral ocellus; RLOc, right lateral ocellus; OcN, ocellar nerve; LP, lobula plate.