“Analysis of the constituents of the metazoic secondary part provides a new criterion for distinguishing between animals and plants and gives logical meaning to its distinction. Animals can be characterized as having sodium as the cation of their metazoic compartment; from the cell level on, they have had the sea as their temporary or even permanent environment. Plants, on the other hand, have potassium as the principal cation for their metazoic compartment, indicating that, from the cell level on, they have had the earth’s crust as their environment, passing thus directly from mud to air. By their actual attachment to the soil, plants continue this relationship to the mud. Their relative immobility is in accord with continuation of the terrestrial-air environment in their development. The mobility of animals, on the contrary, can be seen to have its origin in the fact that they have had the sea as their environment at least for a period of time, i.e., from the cell period until the appearance of those animals which left the sea. We can interpret the appearance of cellulose and lignin as part of the plant-sustaining means which would bring to plants indispensable external protection against the hardness of the soil environment. Cellulose and lignin are not necessary for animals which experienced much of their evolution in the sea.”