Zoology as a discipline specifically caters to the study of animal kingdom. The aim of this book is to present researches that have transformed this discipline and aided its advancement. Detailed studies on the structural, physiological and evolutionary processes of animals are provided in this book. It will serve as a valuable source of reference for graduate and post graduate students of zoology, veterinary sciences and allied disciplines. Those in search of information to further their knowledge in this field will be greatly assisted by this book.