“…The facts presented strongly suggest that chromosome movements can not be merely passive, as believed by WASSERMANN (1926) and SCHAEDE (1925, 1927, who assume that chromosome movements at anaphase are due either to currents produced by changes in viscosity or by vortical currents of the spindle alone. Similarly, the hypothesis of BLEIER (1931,1933) and KORPERICH (1930), according to which the spindle is only necessary for the poleward orientation of the chromosome, can not be upheld in view of the observations presented above.…”