DEVELOPMENT OF THE «END APPARATUS» AND EXCRETORY DUCT IN THE VAN DER VECHT GLANDS OF POLISTES GALLICUS (L.) (HYMENOPTERA VESPIDAE)

Abstract

SUMMARY The development of the end apparatus and excretory duct is described in the Van der Vecht glands of Polistes gallicus (L.) (Hymenoptera Vespidae). The precocious gland buds consist of clusters of three blastocytes wrapped round each other. The external cell represents the prospective secretory cell, and the inner ones the accessory (or ductular) cells. Numerous cytoplasmatic processes emanate from the apical surface of the external blastocyte: microvilli and a long axonemal structure, which act as moulds in the synthetic processes of the cuticular end apparatus and excretory duct respectively. These processes are performed by the prospective secretory cells (end apparatus) and accessory cells (excretory duct). The above findings are discussed and compared with the current morphogenesis patterns concerning the development of the secretion collection and release complex in the exocrine glands of Arthropoda. The fundamental role of cytoplasmic outgrowths during their development is emphasized.