X. The Crawfish, the Spider and the Fly
If you were giving Mr. Crawfish, Mr. Spider and Mr. Fly their places in the long line of march, wouldn't you put them in the order I have named: first Mr. Crawfish, then Mr. Spider, then Mr. Fly?
I would, judging just from the looks of them. I would put Mr. Spider next to Mr. Crawfish. He certainly looks a great deal more like Mr. Crawfish than Mr. Fly does.
But we would both be wrong; for the spider is farther advanced in the scale of life than either the crawfish or the fly. So we would have to ask Mr. Fly to fall in behind him in the "procession."
Yet we must not forget there are some things in which the spider is more like the crawfish than the fly is. In form it is plain, he is more like the crawfish.
And, in one thing, the oyster is more like the crawfish than either the spider or the fly. In what way? The oyster has lime in his shell, just as the crawfish has, only a great deal more of it; while flies and other insects have no lime in their shells. Or, to put it in another way, Nature stopped using lime when she made the insects, and took it up again when she got to oysters.
Nature is a great artist in form, in color, in music; she never strikes notes that are too near each other.
Strike two notes on the piano that are side by side and see how they sound. They don't sound "right," do they? And if you play too slowly—letting the sound of one note die away entirely before you strike another, you don't get much of a tune. To make a tune, one note must run into another—the sound of one beginning before the other has stopped.
So, as you see, Nature playing her great harmonies of form and color and sound, you will notice these two things: She doesn't make the different orders of things too much alike. And yet the differences are not so great that you lose the connection.
Now, look again at Mr. Crawfish, Mr. Fly and Mr. Spider. There they go in just that order—one, two, three. Mr. Spider, although he looks so much more like Mr. Crawfish than Mr. Fly, doesn't come next to him in the procession. Doesn't it look as if Nature "skipped a note" when she made him?