X 
TABLE OF CONTENTS 
CHAPTER PAGE 
XX. The Leaf. .... 274 
XXI. Other Flowering Plants.295 
XXII. The Simplest Green Plants.304 
XXIII. Smallest Plants, Bacteria.309 
XXIV. Fungi — Plants That Lack Chlorophyll . . .320 
XXV. Mosses and Their Allies.328 
XXVI. Ferns and Their Allies.333 
XXVII. The Conifers (Gymnosperms) — Forests .... 341 
XXVIII. Peculiarities of Plant Life.366 
XXIX. Some General Plant Problems.380 
PART III 
HUMAN BIOLOGY 
XXX. Resemblances between Man and the Other Animals . 399 
XXXI. Digestive Organs and Food.404 
XXXII. Movement.432 
XXXIII. Respiration and Excretion.443 
XXXIV. The Nervous System of Man.466 
XXXV. The Biology of Disease.487 
XXXVI. Prevention of Disease.497 
XXXVII. Biology and Human Progress.521 
PART IV 
GENERAL BIOLOGY 
A Summary and Review.539 
Index . 
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