The effect of ultracentrifuging on the cells of the root tip of the bean ( Phaseolus Vulgaris)

Abstract

In several recent papers (Beams and King, 1934, a , b ; 1935; Beams, Muliyil and Gatenby, 1934) we have reported results on the effects of ultracentrifuging various animal somatic cells. We have shown that many of the cytoplasmic and nuclear materials could be readily displaced and stratified into distinct regions according to their relative specific gravity. Up to this time practically no work had been done on centrifuging animal somatic tissues with the exception of that on blood. The main deterrent in this type of investigation seems to have been the lack of sufficient centrifugal force available to displace materials of relatively little difference in specific gravity in these highly viscid cells. The results of our studies on ultracentrifuging animal cells seem to warrant the application of this technique to the study of plant tissues. Accordingly, we have used it as an experimental method, supplementing the usual cytological procedures in an attempt to cast some light on the debated and much confused problems concerning the structural elements of plant cytoplasm.