A comprehensive textbook on human anatomy, physiology, and hygiene, written for students in middle and high school. The book provides a detailed overview of the major structures and functions of the human body, as well as practical advice and guidance for maintaining good health and hygiene. The author, Henry Newell Martin, was a distinguished physiologist and medical educator. This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work is in the "public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.