[Ultrastructural studies on the spermatogenesis in diploid and triploid types of Paragonimus westermani]

Diploid and triploid types of Paragonimus westermani were compared in the aspect of ultrastructure of spermatogenesis. The results showed that the process of spermatogenesis in the diploid type was normal. The cells at every stage are well developed. A great number of morphologically and functionally normal spermatozoa could be formed. On the other hand, the process of spermatogenesis in the triploid type was abnormal, the cells at every stage developed abnormally. They were apparently degenerated or vacuolated, lacking organelles. The cytophore was broken into small particles. No normal spermatozoa were found (Figs. 1-5).