The primary objective of this book is to point out the story of Vertebrate evolution as simply as possible. The book has been divided into two parts. Part one includes a thorough description of the Protochordata which are believed to be the precursors of the vertebrates. The Hemichordata, now considered to be a Non-chordata, has been included in this book because in many syllabi it still goes with the Cephalochordata and Urochordata. Emphasis has also been given to the phylogeny of each type.
Part two includes the description of those Vertebrate types that form the basis of study. The origin, morphology, anatomy and classification of various animal groups have been dealt with in full details. The book also carries a complete work on the embryology of frog, chick and mammals. Some topics of interest related with each Vertebrate group, have also been added. All the illustrations in the book are simple, clear and self-explanatory.