Synopsis Animals are our constant companion. Without them the ecological balance on earth cannot be maintained, and therefore, life cannot grow or sustain itself. There is also, the cyclic food chain that intricately works as a natural law because of the existence of animal world. The author tells the inquisitive student about two broadly classified groups of animals -the Invertebrates and Vertebrates. He explains the scientific principle of classification into genus, species, order and phylum of the more than 1.2 million known members of the animal kingdom. The book is amply provided with attractive photographs, drawings, tables for clear understanding and comprehension.