トノサマバッタ (Locusta danica Linnaeus) の精蟲發生に於ける染色體變異

抄録

In the study of the chromosomes in Locusta danica L., one of the commonest Acridian insects, I have found chromosomal variations, due to the presence of from one to four extra chromosomes beyond the type number of the species; these are assumed to be due to the fragmentation of original chromosomes. Different numbers of fragments appear simultaneously within the same individual at mitosis and meiosis. Such numerical ariations of chromosomes in the germ line have been found in every individual collected by me in Hokkaido. But I can not determine whether the variations are a genetical character of this species or whether the abnormal phenomena accidentally occur in the individuals which were examined, since they are too few. Consequently the present paper is confined to a brief account in regard to the behavior of the extra chromosomes in meiosis.