Studies in Spermatogenesis (Part 2 of 2) by Nettie Maria Stevens

In Part I of this series of papers, the spermatogenesis of five species belonging to four different orders of insects was considered. In two species of Orthoptera an “accessory chromosome” was found; in Tenebrio molitor, one of the Coleoptera, an unequal pair of chromosomes was described; in the other species no heterochromosomes were discovered. The apparent bearing of the chromosome conditions in Tenebrio molitor on the problem of sex determination has led to a further investigation of the germ cells of the Coleoptera.