In order to improve the regulation of abalone 'fishing' and to provide for the restocking of supplies, more details of the reproductive cycle were sought. Attention is given to gonad morphology, acquisition of sexual maturity, juvenile hermaphroditism, gonad histogenesis and histology of gametogenesis, annual cycle of gamete emission, and the relation between size and fertility. Results are presented in graphs, histograms, diagrams and photographs. It was found that female reached sexual maturity during the 3rd year, at 38-54 mm, male during year 2 at 25-40 mm; there was successive juvenile hermaphroditism; an active period from mid-June to mid-November was indicated by the volumentric index of maturity; water temperature was associated with the reproductive cycle, the highest temperatures coinciding with maximum for 7.5 cm individuals increasing to > 5 x 10 super(6) for those of 11.5 cm.