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_)?