Intercellular spaces-digieduco

  In young condition (e.g. the cells of meristematic tissue), the cells are compactly arranged without showing any space between them. As cells mature, the contact between the adjacently situated cells is gradually broken down, so that some spaces called intercellular spaces develop between cells. Intercellular spaces may vary in shape and size-this is due to the difference in shape and arrangement of the surrounding cells. Large intercellular spaces are called chambers while much elongated ones are called canals. Functionally intercellular spaces generally form aerating or conducting systems. They often contain air or water. 

Different stages of the development of intercellular spaces 

According to Martens (1937, '38), the origin and development of intercellular spaces takes place as follows :- when the new primary walls are formed between the two daughter protoplasts (formed as a result of cell division), the middle lamella between primary walls comes in contact with the inner surface of the primary wall (of the mother cell) and not with the old middle lamella cementing the mother cell wall to that of its neighbour ; as a result of this, new and old middle lamellae are separated by a cellulose wall. At the point of contact between the new middle lamella and the inner surface of the primary wall of the mother cell, a small cavity arises. Next the mother wall becomes dissolved opposite the cavity-as a result, the intra-wall cavity develops into an intercellular space. Sometimes, the origin of intra-wall cavity is preceded, accompanied or followed by the formation of a separate cavity within the old middle lamella-this cavity is truly intercellular. These two cavities may thus fuse giving rise to a larger mature space. 

Types of intercellular spaces.

There are two types of spaces, viz. (a) schizogenous and (b) lysigenous. When spaces are “formed by the separation of walls followed by the retraction of the separated parts or by spatial movements of the cell ”, the spaces are said to be schizogenous. Resin ducts of conifers, the secretory canals or ducts of some angiosperm families like Compositae, Umbelliferae etc. are the examples of schizogenous spaces. When spaces are formed by the disintegration ofentire cells, they are said to be lysigenous. Oil cavities of citrus fruits, large air spaces of water plants are the examples of lysigenous spaces. Sometimes cavities are also formed by the combination of those two methods-such cavities are called schizoIysigenous ; examples are the protoxylem lacunae of maize (Zea mays).