To return to the young Spiders: they grow no larger until after they leave their mother. At the age of seven months they are the same as at birth. The egg supplied the food necessary for their tiny frames; and they do not need more tissue-forming food as long as they do not grow. This we can understand. But where do they get the energy-food that makes them able to move about so actively?
Here is an idea. What is coal, the energy-food of the locomotive? It is the fossil remains of trees which, ages ago, drank the sunlight with their leaves. Coal is really stored-up sunlight and the locomotive, devouring it, is devouring sunlight.
Beasts of flesh and blood act no otherwise. Whether they eat one another or plants, they always live on the stimulant of the sun’s heat, a heat stored in grass, fruit, seed, and those which feed on such. The sun, the soul of the universe, is the supreme giver of energy.
Instead of being served up in food and being digested through the stomach, could not this sun-energy enter the animal directly and charge it with activity, just as the electric battery charges an accumulator with power? Why not live on sun, seeing that, after all, we find nothing but sun in the fruits which we eat?
The chemists say they are going to feed us some day on artificial food-stuffs put up in drug-stores. Perhaps the laboratory and the factory will take the place of the farm. Why should not physical science do as well? It would leave to the chemist the preparation of tissue-forming food; it would give us energy-food. With the help of some ingenious apparatus, it would pump into us our daily supply of sun-energy, to be later spent in movement, so that we could keep going without eating at all. What a delightful world, where one would lunch off a ray of sunshine!
Are we dreaming, or will something like this happen some day? It is worth while surely for the scientists to think about it.
THE FLIGHT OF THE BABY TARANTULAS
As the month of March comes to an end, the mother Tarantula is outside her burrow, squatting on the parapet at the entrance. It is time for the youngsters to leave her. She lets them do as they please, seeming perfectly indifferent to what is happening.
The departure begins during glorious weather, in the hottest hours of the morning. First these, then those, of the little ones, according as they feel themselves soaked with sunshine, leave the mother in batches, run about for a moment on the ground, and then quickly reach the trellis-work of the cage in my laboratory, which they climb with surprising quickness. They all make for the heights, though their mother is accustomed to stay on the solid ground. There is an upright ring at the top of the cage. The youngsters hurry to it. They hang out threads across the opening; they stretch others from the ring to the nearest points of the trellis-work. On these foot-bridges they perform slack-rope exercises. The tiny legs open out from time to time as though to reach the most distant points. I begin to realize that they wish to go higher.