Like the chicken's gizzard the gizzard of the earthworm is lined with a thick, tough membrane, and it has muscles—such muscles! There are two sets of these muscles and they cross each other somewhat like the warp and woof of the cloth in your clothes. The muscles that run lengthwise are not so very strong, for all they have to do is to help the earthworm swallow, but the muscles that run around the gizzard are wonderfully strong. They are about ten times as thick as the other muscles. One of Mr. Earthworm's French biographers[10] calls these muscles "veritable armatures"; that is, freely translated, "veritable hoops of steel."
I said, in the second paragraph above this, that worms swallow grains of sand and stones to help their digestions, as chickens do. But the earthworm saves time, for he takes the stones with his meals; just as some Englishmen, fat old squires, when they get along in years, or for any other reason are a little weak in their digestive regions—keep pepsin on the table with the pepper and salt.
And—believe it or not—the earthworm actually makes his own millstones sometimes! The chalk in the chalky fluid of the glands that help him digest his meals frequently hardens into little grains in grinding the food. It's almost as if the saliva in our mouths, in addition to acting directly on the food, also made a new set of teeth for us!
Suppose we had a stomach like the earthworm, wouldn't it be fun? We could digest the biggest dinners at Thanksgiving and Christmas and picnics and birthdays. We could even eat apples without waiting for them to get quite ripe. Haven't you done it to your sorrow? And no stomachache and no mince-pie nightmares!
WHY THE EARTHWORM NEVER HAS NIGHTMARES
By the way, the earthworm, although he has his troubles like the rest of us, never has nightmares. For one thing he has that stomach[11] and—a still better reason, perhaps—he never sleeps at night. Like the moths and the bats and the burglars and members of Parliament, he makes night his busy day.
And, in other ways, while he is so much like the rest of us worms of the dust, his life differs from that of most people. For instance, he not only works by night while we work by day, and works underground while we work on top, but he takes his vacation in the Winter while we take ours in Summer. In that respect Mr. Earthworm is like the millionaires at Palm Beach; for in Winter he, too, goes in the direction we call south on the map—that is to say down.
But, as you say, it takes all kinds of people to make a world; including earthworms and millionaires!
HIDE AND SEEK IN THE LIBRARY
Who was that in Mother Goose that went a-fishing "for to catch a whale"? Anyhow, there are fishworms so big that one might suppose they were made for catching whales. How long do you suppose they are, these big fishworms? A foot?
Pshaw! We have fishworms of our own a foot long. Two feet? More. Three feet? More. You look it up in the article on the earthworm in the "Britannica."
And how many kinds of earthworms do you suppose there are? You will be surprised to learn.
Also, you will find that the earthworms have relatives who live in the water all the time.
The article in the "International" tells why these modest neighbors of ours don't come to the surface in the daytime. That will be an interesting thing to know. Don't you think so?
And did you ever count an earthworm's rings? Other scientists have. (All live boys and girls are scientists; they want to know.) Try counting the rings of an earthworm and then compare your figures with those given in the article in the "International."
How many hearts do you suppose an earthworm has? You will find in the "International's" article they have a good many of what are sometimes called "hearts," and how different the earthworm's circulation system is from ours.
Does our saliva do for us anything like what it does for the earthworm; and our pancreatic juice?
Compare the earthworm's method of digging his subway with that of the armadillo. How do they differ in the way of using their noses?
Do you know how men dig subways; like those under New York City and Boston, for instance? Books that tell about this phase of human engineering and tell it in a very interesting way are "On the Battle-front of Engineering" ("New York's Culebra Cut") and "Romance of Modern Engineering" ("City Railways"), "Travelers and Traveling" ("How Elevated Roads and Subways Are Built").
Speaking of the earthworm's wedge and how he uses it, do you know that all of man's complicated machinery is the result of only a few simple mechanical principles combined; and that the wedge is one of the most important? Look up "wedge," "machine," "simple machine," etc., in the dictionary or encyclopædia.
How does the earthworm's method of pushing his way in the world with the end of his nose compare with the way a root works along in the ground? (See [Chapter X].)
The earthworm's neat way of disposing of the dirt he casts out reminds me of how the beaver handles dirt when he builds a canal, and the way of the ants in digging their underground homes. (Chapters [VI] and [VIII].)
We have little brains in our finger-tips just as the earthworm has on the end of his nose. How much do you know about the little brains scattered through our bodies (Ganglia)?
You see the simple earthworm is the A, B, C of a lot of things; and even Mr. Darwin's famous book doesn't contain all there is to be learned about him in books and in personal interviews with Mr. Earthworm himself. A farm boy to whom the writer read the story of the earthworm, when asked how he thought the worm could turn in his burrow when it fits him so closely, said, "Why, he turns around in that little room at the end of the hall," thereby solving, as I think, a problem that puzzled Mr. Darwin, and which he left unsolved.