Some Criteria for Judging the Degree of Polyploidy of Cells in the Resting Stage

Abstract

Known criteria are evaluated and a new criterion is given. Spinacia (n=6) has 1 satellited chromosome. In the resting nucleus the satellites are heteropycnotic and appear as a pair of small chromatic spheres either in contact with the nucleolus or connected to it by fine threads. In the tetraploid and octoploid cells which occur normally in Spinacia root tips 4 and 8 of these pycnotic satellites can be counted in the clear zone surrounding the nucleolus.