Fig. 4

Retrograde tracing of nerves associated with the ventral nerve cords in Onychophora. Maximum projection confocal micrographs. Retrograde fills with dextran coupled to either tetramethylrhodamine or fluorescein. Anterior is up (a) or left (b–d). Median is left (a), up (b–d) or down (e). a Position of neuronal cell bodies associated with ring commissures, and the anterior and posterior leg nerves in Euperipatoides rowelli. b–d Position of motor neurons associated with the anterior and posterior leg nerves in E. rowelli (b) and a separated depiction of the anterior (c) and the posterior leg nerves (d) of the same labelling as in b. e Position of somata associated with two subsequent median commissures in Principapillatus hitoyensis. al, anterior leg nerve; mc, median commissure; rc, ring commissure; pl, posterior leg nerve. Scale bars: 100 μm (a) and 50 μm (b–d)