From ZooTerms (Dictionary of Invertebrate Zoology)
apex of a structure distinguished by location, shape, size and function.apical cell: 1. A cell situated at the
2. (Arthropoda: Insecta) Apical testicular cell of Orthoptera, Dictyoptera, Diptera and Homoptera, and some Lepidoptera, that supplies mitochondria to the spermatogonial cytoplasm during spermatogenesis; Verson's cell; Versonian cell.