Seashells more than a home

Every day, seashells wash up on beaches all over Earth, like treasures from a secret world beneath the waves. Spiraled or spiky, round or ridged, shells come in all sorts of shapes and sizes, and all the colors of the rainbow. That's because seashells have so many different jobs to do             Seashells can rise and sink like a submarine . . .             A nautilus floats because most of its shell is filled with a lightweight gas. To dive down it pumps water into its shell. When the nautilus wants to rise toward the surface, it lets water flow out of its shell. Excerpted from Seashells: More Than a Home by Melissa Stewart All rights reserved by the original copyright owners. Excerpts are provided for display purposes only and may not be reproduced, reprinted or distributed without the written permission of the publisher.