Note 3 — XIX PROTOPLASM, LIFE AND DEATH

Protoplasm is not a single chemical compound; it is the name given to the soft, slimy substance of cells, and contains many chemical compounds—proteids, fats, and others; some on the way to assume greater chemical complexity; others in process of destruction. The critical highest chemical body concealed in protoplasm has no generally recognised name. It is a proteid-like body, consisting chiefly of carbon, oxygen, hydrogen, and nitrogen, with some saline constituents. This is the real ultimate “living matter,” and I suggested in the Encyclopedia Britannica (article Protozoa) in 1886 that it should be called “plasmogen.”