Chromosome Alterations Caused by Hybridization and Their Bearing upon Certain General Genetic Problems

Abstract

Introduction Several years ago the present writer began a series of caryo-logical investigations on interspecific Crepis hybrids with the principal aim to compare the specific chromosomes under exactly equal conditions of the common hybrid cell. It was a great surprise to find (M. Navashin, 1927) that the chromosomes of two or more different species brought together by hybridization in certain specific combinations suffer striking alterations of their individuality. This phenommenon termed by the present writer amphiplasty (1928) was many times observed since and was verified on an extensive material. Other investigators confirmed the original observation partly on same material (Hollingshead, 1930, on Crepis capillaris x C. tectorum) partly adding new cases to those previously reported (Avery, 1930).” A series of observations and experiments have made it possible to obtain some broader information regarding the nature and the significance of the phenomenon in question. In the following will be given the results of these investigations performed in the period of 19281930. © 1934, Japan Mendel Society, International Society of Cytology. All rights reserved.