Part 13

Is the Embryo different from others?

In general it is like an undivided cylinder, but in Grass and Corn, it is a flat plate.

What! is Corn like the Palm, father?

Yes; for although it has a second, unshapen lobe, it is truly monocotyledonous.

Well, father, how does the growth of the Mono folks go on?

In the Palm embryo are noticed bundles of fine tissue, arranged circularly from the plumula to the radicle. These tissues increase and shoot downwards. The cellular tissues of the embryo now enlarge to make room for woody fibres, which begin to appear. A rootlet is formed, and a leaf comes forth.

But how is the stem formed?

There are several crown leaves springing from the root in a circular form, each circle with its own cluster of vessels. Each leaf bud sends out a lot of woody bundles, curving downwards and outwards, which become entangled irregularly in the cellular tissue.

That is how it is that there seems no order and arrangement about the wood of a Palm or Fern tree. All is higgledy-piggledy, and the moist stuff must be collected near the circumference. But what is the soft centre made up of?

Cellular tissue, of course. You can distinguish no pith, no medullary rays, and no distinct bark, like our fruit trees.

No, I see that which ought to be the bark is a jumble of fibres, which cannot be separated from the stem as in the regular trees. I don’t like these monocotyledonous trees; they seem quite ungainly and unnatural.

And yet you have no objection to the bread of corn, the sugar of the cane, the nut of the cocoa, the date of the palm, the banana, the yam, the arrow-root----

Stop, stop, father, you have given such a list of good things, that I will never say a word against the monocotyledonous family as long as I live, though I do wish the botanists would give them a name that boys could pronounce better.

Something must be said about the leaves of these curious plants. Instead of their veins being branched out, the leading ones run parallel, and are connected by small cross veins. For this reason an injury to any part of a palm leaf is of much more consequence than if it happened to a gum leaf. You have seen that the leaves are the true organs by which woody matter is formed, and not the inner bark, as with other trees.

Is there any peculiarity about the flowers of Endogenous trees?

Their petals, stamens, and pistils, are generally in threes or sixes. The palm has usually six stamens. Half the plants of New Zealand are monocotyledonous, being far more than in Australia.

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Will you please, father, say a few words about the third sort of plants--the Acotyledonous?

These are cellular, and have no apparent flowers.

But how do they propagate or spread themselves, if they have no regular seeds?

They have little things called Sporules, or Spores, without spiral vessels, which are the means of increase. Mosses have capsules, with teeth, as before mentioned; the fringe enclosing a rude kind of flower. Some of these are barren, and others fertile. The latter may have several imperfect pistils along with one perfect one.

I have half a mind, father, to fancy that the common fern is one of the acotyledonous.

Some botanists think the same. The seeds are formed upon the back and margin of the fronds or leaves, in the form of bud-like spores. They are exceedingly small, and no flower is visible to the eye.

Do these spores, like seeds, produce stem from one part, and root from the other?

No, my boy, the little globular things have no plumula and radicle; but that part which is exposed to the light produces stem, and from the shaded portion the root descends.

Are other plants produced from spores?

Yes, Willie, the mushrooms and sea-weed are. The productive organs of lichens, the most imperfect of plants, are the Shields, as they are called, upon the Thallus, or leaf-stem.

Well, father, I think now we have gone over all the different sorts of plants and trees, and I feel myself the wiser for your kind and pretty lessons. I shall be a regular botanist now.