Comparative study of the reproductive organs of Fasciola groups by opticalmicroscope

Reproductive organs of stained and mounted whole specimens of different typ es of Fasciola (F. hepatica, F. gigantica, and parthenogenetic diploid and triploid flukes) were observed to clarify the structure of their reproducti ve organs. The results are as follows; 1. Basic structure differences could not be identified. 2. The flukes without sperm, or those with an extremely small quantity in the seminal vesicle, are parthenogenetic Fasciola sp. 3. It was newly discovered that the surface of the cirrus is surrounded by ma ny shallow gutters, and that spines form a line in the gutters. 4. The stru cture of the reproductive organ on the genus Fasciola are shown in detail i n the figures.