AN ULTRASTRUCTURAL-STUDY OF THE MATURE SPERMATOZOID OF THE FERN ASPLENIUM-TRICHOMANES L SUBSP TRICHOMANES

Asplenium trichomanes L. subsp. trichomanes spermatozoids are spirals of about five turns. Keels link the elements of the microtubular ribbo n with the plates of the lamellar layer (LL) which are uninterrupted, parallel and curved with an inner angle of about 150 degrees, Electron -opaque filaments connect the microtubules of the multilayered structu re (MLS) and the osmiophilic crest, the LE and the MLS-associated mito chondrion and the latter and the plasmalemma. The nucleus occupies the 2.5-3 posterior turns and has an inner honeycomb-shaped chromatin mas s and an outer highly condensed chromatin mass with randomly scattered electron-transparent areas. The basal bodies of the ca, 50 flagella a re bounded by a reticulum of granular material which forms a plug insi de their proximal region: the proximal region of the flagellum has a 9 + 0 pattern. The axoneme has a 9 + 2 pattern.