Middle Lamella ii. Primary Cell Wall iii. Pits are depressions in the cell wall that are circular to oval where the secondary cell wall is the portion of the cell wall that is hollowed out to make the pit ii.
Pits are adjacent to one another on either side of the cell wall iii.
Thus, pits come in pairs and are called pit pairs iv. The pit membrane is composed of the primary wall and middle lamella of the adjacent cell walls of the pit pairs v. U-shaped in morphology vi. Similar to the simple pit ii. The secondary cell wall forms a border over the pit membrane leaving a small opening called a pore iii. In the center of the pit membrane is a knob of secondary tissue called a torus iv.