By careful focusing it is easy to show that the protoplasm is confined to a thin layer lining the wall, the central cavity of the tube being filled with cell sap.
This fluid, which in most cells is colorless, is called the cell sap, and is composed mainly of water.
The solution that these molecules are stored in is called the cell sap.
Here they develop further and become sedentary, burying their heads in cells and feeding on the cell sap.
They live between the cells of onion or garlic leaves and between the scales of the bulbs where they feed on cell sap and multiply.
Pigments that color the cell are sometime located in the cell sap.
