assistance in the preparation of the chapter on microörgan. isms. A considerable part of the "Human Biology" was critically read by Dr. F. C. Waite of the Western Reserve Medical School, by Mr. Harold E. Foster of the English Department of the Morris High School, and by the late Miss Martha F. Goddard of the Morris High School, to whose memory these volumes are dedicated. To Mr. E. R. Sanborn of the New York Zoölogical Park, and to Mr. A. E. Rueff of the Brooklyn Museum, we are indebted for their skillful photography. The American Museum of Natural History, the Brooklyn Museum, the National Aubudon Society, Doubleday, Page & Co., Dodd, Mead & Co., Kny-Scheerer Co., Dr. C. F. Hodge of Clark University, Dr. H. A. Kelly of Johns Hopkins Medical School, Mr. C. W. Beebe of New York Zoological Park, and others, have permitted us to make use of illustrative material. Cost prices for the items on the list of laboratory apparatus and equipment were kindly furnished us by Bausch & Lomb, Kny-Scheerer, and O. T. Louis; from these prices the estimates on pp. 173 to 177, Appendix I, were prepared. J. E. P. December 31, 1912. A. E. H. V. ADAPTATIONS OF THE NUTRITIVE ORGANS OF PLANTS I. The Structure and Adaptations of Roots II. The Structure and Adaptations of Stems III. The Structure and Adaptations of Leaves. I. Seeds and their Development into Plants ДАРТЕР V. CRAYFISHES AND THEIR RELATIVES. VI. PARAMECIUM AND ITS RELATIVES I. Structure and Functions of Paramecium II. Structure and Functions of Amoeba |