If in the cytoplasm of a cell there are two points of molecular concentration greater than that of the general mass, the nucleus must necessarily divide with all the phenomena which accompany karyokinesis.
"The Mechanism of Life"
Stéphane Leduc
Thus the cell becomes organized, forming its own cytoplasm and its own enveloping membrane.
"The Mechanism of Life"
Stéphane Leduc
We may infer that cell-evolution was, under one of its aspects, a change from a stage in which the exciting substance and the substance excited were mingled with approximate uniformity, to a stage in which the exciting substance was gathered together into the nucleus and finally into the chromosomes, leaving behind the substance excited, now distinguished as cytoplasm.
"Herbert Spencer"
J. Arthur Thomson