CORNUAL GLAND OF THE HONEYBEE DRONE (APIS-MELLIFERA L) - STRUCTURE AND SECRETION

The cornual gland of the drone's endophallus is an epithelial gland, w hose cells extend from the tip of the cornual tube, along its lateral parts to the basic hump (dorsal cornua). The gland forms a stripe with a central region of dense and homogeneous secretory cells. To the sid es the gland cells become sparse. The secretory cells contain mainly r ough endoplasmatic reticulum and numerous mitochondria. The nuclei hav e several nucleoli and are situated at the apical part. Microvilli bor der the microfibrillar cuticula into which cell projections often intr ude. At the basal membrane the cells are often subtended by a layer of fatty tissue, and oenocytes can also be attached. The secretion in a 3-day-old drone appears either as an orange-coloured layer (deep froze n sections) or as osmiophilic granula (EM) mainly near the lumen of th e cornual tube. The cuticula of the cornual tube is untanned and non-s clerotized. Along the lumen of the cornua it is extremely folded and p apillated, forming in situ small cavities which contain osmiophilic dr ops of the secretion, often accumulated in groups. No pores were found , although small granules of secretion occur within the cuticular laye rs, with the highest concentration near the lumen. During eversion of the cornua the secretion merges on the surface of the cuticula. The cu ticula consists of two differently structured layers. Near the lumen o f the cornual tube the microfibers extend regular and parallel to the folds; above the gland cells the microfibers are less dense and more i rregular.