The fine structure of the male genital organs of Allacma fusca (L.) (Collembola, Symphypteona)

The fine structure of the male reproductive system of Allacma fusca (L.) is described. The system consists of testes, deferent ducts, seminal vesicles , ejaculatory duct and accessory glands. The nature of each part is establi shed, Secretions from the seminal vesicles are stored in the lumen of these organs, then flow into the ejaculatory duct and are used to produce sperma tophores. The epithelium of this tract has secretory activity and osmoregul atory function. Secretions and spermatozoa are stored into two distinct par ts of the ejaculatory duct, divided by a transverse cuticular septum.