UMEA UNIVERSITY MED.DISS. 286,531 OSTBERG YNGVE new series 15 The entero-insular endocrine organ in a cyclostome, myxine glutinosa . A light and fluorescence, microscopical, histochemical and ultrastructural study,aiming to give some evolutionary aspects on the origin of islet parenchymal cells and the entero - insulr axis . Umea 1976 Universitet 4 °s . 41 , il . +wkł. s . nlb .2. Umea University Medial Dissertations new ser . 15 Akademisk avhandlin