Part 16

“Why does the flower-head keep closed when the seeds are ripening?” asked Tom.

“Because,” answered Uncle George, “not only has the seed to ripen, but a plumed stalk has to be formed by means of which the seed is carried away from the parent plant. These plumes have to be perfectly dry or they would be of no use as sails to the seed. Notice that it is only on dry days that these ‘clocks’ of the dandelion appear.”

“But, Uncle George,” said Frank, “are these seeds actually fitted with feathery tops so that they may be carried far away from the parent plant?”

“Certainly, my boy. You would not have them all trying to grow in the place where the parent plant grows, would you? There would be no room for three hundred seeds to grow there. Besides that, the parent plant has already exhausted the soil. It is necessary that they should seek pastures new, and therefore the seeds of most plants are furnished with some means of travelling.”

“Are all seeds carried by the wind?” Tom asked.

“Oh dear no,” Uncle George replied, “plants have many ways of scattering their seeds. Some plants, by suddenly bursting their seed-vessels, shoot their seeds far out; some seeds are furnished with little hooks which grip on to the fur of passing animals; some are carried by birds; but by far the greater number are scattered by the wind.

“We shall learn more about these at some future time. Meantime we will grow a dandelion plant at home, and watch the opening and closing of its flowers, and the wonderful way in which its travelling seeds are produced.”

Exercises on Lesson XII.

1. Gather dandelion flowers at different stages of growth. Draw, on a large scale, a single floret from each, 2. Draw a leaf of the dandelion. Compare it with a primrose leaf. See if you can make out, from the shape of the leaf, why the plant is called “dandelion” (dent de lion = “lion’s tooth”). 3. Take in a dandelion plant bearing young flowers. Keep the root in well-watered soil, or in water only, and watch the growth of its flowers. 4. Make a list of all the wind-carried seeds you know, and give a drawing or short description of each.

XIII.—TROUT.

One day in November the postman brought Uncle George a small wooden box. There were holes bored in the sides and top of it. The box, when opened, seemed to be filled with damp moss; but when some of this moss was removed there was found in the middle of the box a piece of folded muslin.

Hatching Bottle. A. Supply pipe. B. Exhaust pipe. C. Trout Eggs. Rearing Box. C. Perforated zinc tray to fit box.

Uncle George laid the muslin on the table, and opened it out. It contained a number of tiny pink balls, much smaller than peas.

“These are the trout eggs you promised to get for us, are they not?” said Frank.

“They are,” said Uncle George, “and we must put them into running water at once. I have a bottle here ready for them.”

Uncle George filled a wide-mouthed bottle with water from the tap and placed the eggs in it. He then corked it with a cork in which he had bored two holes.

Into each of the holes he had fitted a tube. One tube was long enough to reach almost to the bottom of the bottle. The other was bent over the outside of the bottle.

The straight tube was connected with the water tap by a piece of indiarubber tubing. He then turned the tap on gently, so that the water went in by the straight tube and came dripping out by the bent tube.

“Trout require a constant supply of fresh water,” he said. “Their eggs are usually laid in shallow streams.

“Now, boys, I want you to watch these eggs and note down any changes you see in them. You can remove the bottle from the tap at any time, but you must not keep it more than fifteen minutes at a time, or your trout will not hatch.”

At the end of a week the boys noticed two black dots and a coiled white line in each egg.

In two weeks more some curious-looking creatures were seen wriggling about among the eggs. As there were some empty egg-skins to be seen, they guessed that these lively creatures must be young trout.

They were not a bit like fish. Each seemed to be made up of a long white streak, which looked like the “backbone” of a fish, a big, clumsy yellow bag with red veins running through it, and two large black spots that looked like eyes.

In a few days all the eggs hatched out, and in place of the little pink eggs there was a crowd of these wriggling creatures and a number of empty egg-skins. The boys were puzzled, and Uncle George had to be consulted.

“I don’t think these were trout eggs,” said Frank. “The creatures that came out of them are not a bit like fishes. They swim on their sides and have a huge yellow bag attached to their bodies.”

“They are young trout, I can assure you, Frank,” said his uncle laughing. “If you remember, your tadpoles were not a bit like frogs when they hatched out of the egg. These huge bags you talk of are called ‘yolks.’ Each trout when hatched is furnished with a huge yolk or food supply.

“The tadpole, when hatched, has also got a yolk upon which he lives without eating for four or five days. Our trout will require no food for six weeks. During that time the yolk will become smaller and smaller, and at last disappear entirely. While the yolk is shrinking, you will notice that the creature gradually assumes the form of a fish.”

Uncle George emptied the bottle containing the young trout into a wooden box which he had made. This box was fifteen inches long, four inches broad, and four inches deep. The inside of it he had charred with a red-hot iron after it was put together. It was placed under the tap, and the water dripped into it all day and all night.