Abstract
Reports that have been accumulated by many investigators on ascaris spermatozoon, are able to be divided into two. One is studies on chromosomes of ascaris male pronucleus. Such investigation originating in the work of Bon-nevie (1902) onAscaris lumbricoides, was followed up by Boveri (1910) onA. megalocephala, Edwards (1910), Jeffery and Haetl (1938), and Walton (1924) on the former specimen. But these author's reports were not on the whole process of ascaris spermatogenesis but on the chromosome number, form, and behaviour in its reduction division. The other is studies on its spermatogenesis itself: Bischoff (1855) and Thomson (1856) had observed spermatogenesis inAscaris mystaxand Beneden and Julin (1884), Scheben (1805), Mayer (1908), and Romieu (1911) had made information on that ofAscaris megalocephala. Especially on the work of Mayer (1908) he observed the vicititude of mitochondria in the cytoplasm of spermatocytes and described the formation process of so-called‘Glanzkörper’which was one of characteristics of ascaris spermatozoon morpho-logically.
Materials that have been studied on nematode spermatogenesis were only three species, A. mystax, A. megalocephala, andSprina parasitiferawhich was investigated by Cobb (1928) as a free living marine species. No reports on that ofA. suillawere, therefore, available and the peculiar form of its spermatozoon has attracted the author's attention during our previous studies on its ovogenesis. These two facts furnish the reason why the present study has been undertaken.
