The aspiration of the water from the soil is due to the intracellular osmotic pressure in the roots, which causes the sap to rise in the stem of a plant as it would in the tube of a manometer.
"The Mechanism of Life"
Stéphane Leduc
In general, we may divide luminous organisms into two great classes according as the oxidizable material is burned within the cell where it is formed or is secreted to the exterior and is burned outside-intracellular and extracellular luminescence.
"The Nature of Animal Light"
E. Newton Harvey
Many animals with intracellular luminescence have quite complicated luminous organs.
"The Nature of Animal Light"
E. Newton Harvey