Cover illustration. Morphology of the trigeminal nerve is closely related to the embryonic composition of the jaw or oral apparatus of vertebrates. In this issue of the Journal of Morphology, Higashiyama and Kuratani (pp. 17–38) investigate the development of the maxillary nerve, a component of the trigeminal nerve, generally regarded as a branch specifically assigned to the upper jaw of gnathostomes. The authors tried to reconstruct this branch's evolution by comparative embryological observation. The cover image shows the embryos of the Mus musculus (left) and Scyliorhinus torazame (right) immunostained to visualize peripheral nerves. Trigeminal nerves are highlighted by hand drawing.