Time of Differentiation and Determination of Eupyrene and Apyrene Spermatozoa and Resulting Spermatogenesis in the Silkworm, Bombyx mori L.(Lepidoptera : Bombycidae)

Abstract

The origin of the eupyrene and apyrene spermatozoa, and resulting spermatogenesis were investigated by the histological observation of testes and cytological observation of germ cells. It was found that the time of differentiation and determination of both types of spermatozoa occurred between the stage of the spermatogonia and leptotene stage of the spermatocytes. Furthermore, during apyrene spermatogenesis, it was determined that the disposition of the chromosomes is irregular in meiotic division.