Cells, father! what, like the bees’ honey-comb!
Yes, indeed, and six-sided like those cells. The walls, however, are not made of wax, but of cellular tissue. This tissue is a fine membrane, or skin; or, rather, a transparent, colourless, film. Mucous threads connect the cells.
What curious things to be in a tree?
I shall astonish you more when I tell you that all your tree—root, bark, pith, wood, and leaf—every one of these is composed of a number of these little cells. Do you see those small spots in the wood, and these in this leaf in my hand?
I do, father.
They are thought to be the openings of the cells, through which various juices may pass. Some cells are round and regular, as in the leaf; while those of the wood, from being much crushed, are spindle shaped, like a tap root.
Would they not be round in the fruit, then?
They would, Willie, and are there filled with some nice secretions, that boys rather enjoy. In the pretty leaves of flower, they contain a coloured fluid. Some cells hold carbon, and others have crystals of flint, lime, iron, starch, &c. Sugar, gum, resins, turpentine, &c., are in cells.
That is where the scratching stuff comes from, which I have felt in the cutting grass and wheat straw. But are there cells in roots?
Yes. There are, also, long tubes in plants like our water pipes, which are open at each end, not closed like the cells. They are parallel to the line of the stem, and are extremely small. They may be called elongated or lengthened cells, and form what is called the vascular system, or system of vessels.