† mesistemn.

1884 F. O. Bower & D. H. Scott tr. H. A. de Bary Compar. Anat. Phanerogams & Ferns viii. 394 Russow maintains essentially the same view, calling Sanio's primary pith Endomeristem, the zone surrounding it Exomeristem; the latter is divided into the Mesomeristem, which is the inner layer producing the vascular bundles, and the Perimeristem, which is the outer zone, forming the external cortex and the Dermatogen. Endistem, Existem, Mesistem, and Peristem are abbreviated expressions for these successive layers.