Dictionary.net

• The division of the chromatin to three poles in diseased cells instead of the normal two poles, in mitosis.

1920 - A dictionary of scientific terms.
By Henderson, I. F.; Henderson, W. D.

• [Greek] Appl. the division of the chromatin to three poles in diseased cells instead of the normal two poles, in mitosis (cyt.).

1920 - A dictionary of scientific terms (6th edition)
By J.H. Kenneth