Vlil CONTENTS 



CHAPTER PAGE 



XXVII. Vegetative Propagation 255 



XXVIII. Sexual Reproduction 264 



XXIX. Reproduction of Higher Plants 273 



XXX. Reproduction of Animals 281 



XXXI. Protection of Young 292 



XXXII. Character of Offspring 306 



XXXIII. Heredity . . .318 



XXXIV. Mutations .335 



XXXV. Plant and Animal Breeding 343 



XXXVI. Eugenics 355 



XXXVII. Progressive Development 371 



XXXVIII. Bacteria 391 



XXXIX. Beneficial Activities of Bacteria .... 403 



XL. Health . .413 



XLI. Smallpox and Its Control 420 



XLII. Rabies and Its Control 429 



XLIII. Tuberculosis and Its Prevention .... 437 



XLIV. Diphtheria, Scarlet FE^'ER, and Tetanus . . . 450 



XLV. Typhoid Fever 464 



XLVI. Certain Other Diseases 473 



XLVII. The Control of Malaria and Yellow Fever . . 480 



XLVIII. Defenses against Diseases 494 



XLIX. Immunity 504 



L. Taxonomy 510 



Appendix 529 



Index 551 



