If you were a little beaver you'd have from two to four twin brothers and sisters to start with, and then two to four more for each of the remaining two years before you left home to make your own way in the world. You'd be born with your eyes open and not like a puppy or kitten. And, what do you think, _in less than two weeks_ you could go swimming. Mother would be right with you in case anything happened. Then when you were tired swimming you'd climb up on top of the house and rest and doze in the sun; take your afternoon nap just like any other baby. [Illustration: LITTLE BEAVERS IN THEIR HOME] But maybe it wouldn't be your own mamma that would be with you; for lots of sad things happen to beaver people, and when one little beaver's mother dies another mother beaver will take care of him, and all his brothers and sisters besides! Mr. Mills tells in that most interesting book of his about how one day a mother beaver was killed by a hunter who thought he didn't have anything better to do than kill poor little beavers; and the very next evening a lady beaver, who _already_ had four babies of her own, travelled a quarter of a mile with them to the house of her dead neighbor and stayed there and brought all the little orphans up! HIDE AND SEEK IN THE LIBRARY The crayfish is a thing you've got to take seriously if you want to get the most out of it. Huxley says that a thorough study of a crayfish is almost a whole course in zoology. Think of going to school to a crayfish! But you'd enjoy it, I'm sure. For just look--and these are only a few of the interesting things you will find in Huxley's famous book on "The Crayfish": How they swim backward (no doubt you know this already), and how they walk on the bottom of the water. Why they seem to know the points of the compass--for they prefer rivers that run north and south. Why they are most active toward evening. Where they spend the winter. Why they eat their old clothes. How early in the spring you may expect to find them. When they hatch their eggs and how the mother crayfish uses her tail for a nursery. In what respect they resemble moths. How they chew their meals with their feet and work their jaws like a camel from side to side--only more so! How they grow by fits and starts, and what this has to do with the way they change their clothes. How you can tell the age of a crayfish. (You don't do it by looking at its teeth. You couldn't see its teeth anyway, because they are in its stomach.) And all this in less than the first fifty pages of a book, which has more than 350.