One doesn't forget, it is true, to everywhere find it [i.e. the chemical nature of the structures], but one yet doesn't fully exploit it. F. Duspiva, 1955, writes : "A discovery may be suited to bridge the gap between the molecular processes of the biochemist and the transformation of the visible structures of the morphologist. Recently it has turned out that there are in the cell complex and unstable systems of enzymes with coordinated effect, coming together into functional units, reaching such large a size that they come close to microscopical visibility, or already surpassing it (microsomes, mitochondrians) . . ."