It is as if nature said, after studying the yeast plant: "This yeast plant will make something better if it can get out into the world.' So she took the same sort of little cells out where they could meet the air and the sun, and there came the liver-wort, part leaf and part root, and the first plant to find out how to make spores. Next came the mosses which began to stand up; and then the ferns which gave the vegetable world its backbone. Last of all came the flower-bearing plants, and with it the great partnership between the animal and the vegetable world, each helping the other to live.
But to do all her wonderful work Nature, like you and me, had to work with two hands. While with one hand she was helping the vegetables to get up high enough to receive the help of the animal world, in getting still higher; she had to teach the amoeba how to grow into birds and butterflies and men, so that they could come into this grand plan of things, and make more and more beautiful and useful varieties of animal and vegetable life.
Now, her work with her right hand, in growing the wonderful varieties of animals from the shapeless, formless amoeba, has got along as far as the sponges, which already have mouths and "hands" and the beginnings of bones, and a hollow inside.
Not only have sponges so many more useful and interesting parts than the amoeba, but they show, again, how fast you can make differences when you have more than one part to multiply with. Sponges have many different shapes, different colors, and they live in many different kinds of places. One kind of sponge is called the finger sponge, because it has fingers like the human hand. Another is shaped like a banana. Others are almost as round as a ball. Some look like a flat red mat, spread over the rocks under the water, as if for the entrance to the doorway to some palace of the water fairies. Some are black, some yellow, some brown.
One kind of sponge looks like a beautiful vase of spun glass, and when these sponges were first brought to Europe, from their home in the South Pacific, they were not thought to be sponges at all, but vases made by very skillful workers in glass. They were known as "Venus' Flower Baskets."
The sponge itself is not only made up of other little animals living together, and getting food for one another, but other animals, of a higher order, are often found living in the cosy sponge village. In the larger sponges are found shrimps, crabs and even fishes. See Sponges, page 1801.
