The science of life : fully illustrated in tone and line and including many diagrams

CONTENTS

CHAPTER VY. Tue Growrs of THE INDIVIDUAL

PAGE

§ 1. Normal and monstrous develop- § 6. The limitation and control of ment . 314 growth §2. The new individual settles down S77. Age, retrogression, and rej enato development 3 316 tion § 3. The moulding of organs by use 319 §8. Is human rejuvenation “desir§ 4. The transformation of Tadpoles 321 able ? : $5. The réle of the Genes. eS 29 CHAPTER VI. Wuat Determines Sex §1. The normal causation of sex . 337 § 5. Gynanders § 2. The proportion of the sexes . 338 § 6. Sex hormones § 3. Can we control the sex of our § 7. Reversal of sex children ? ; 340 § 8. Intersexes § 4. Sex-linked inheritance and S€Xdetectors : 5 : . 341 CHAPTER VII. Varration or Species § 1. The open questions of variation 350 $4. Are acquired characters in§ 2. Mutation : the experimenting of herited ? : . the germ-plasm : - 350 § 5. Artificially. -induced ‘mutation $3. Are there forward bounds in § 6. Moths and smoke mutation? . : . 52 § 7. The significance of sex § 8. Variations in plants

CHAPTER VIII. Sezection iw Evoiution

§1. The vindication of Darwinism 364 § 4. Selection of characters useless § 2. Natural selection as a conserva- to the species . tive force : 367 § 5. Isolation as a species- -maker § 3. Natural selection under chang- § 6. Crossing may produce new ing conditions : ‘ . 369 species § 7. Failures to vary and extinction

CHAPTER IX. Is tHere a Mysticat Evoturionary Uren ?

$1. Straight-line Evolution . . 380 § 3. The élan vital and the life force § 2. Do races become senile ? . . 382 § 4. Is there purpose in evolution ? BOOK V

THE HISTORY AND ADVENTURES OF LIFE CHAPTER I. Tue Protocur

$1. The scale of the Universe » 391 $3. The origin of life $2. The setting of the stage . - 393 § 4. Changes i in the terrestrial scenery CHAPTER II. Lire Berore Fossirs § 1. The earliest life : : . 401 § 4. The first brains § 2. Union is strength : the building $5. Blood as a step in ev olution : of the plant-body . 4.01 the ccelomates appear § 3. Marthas and Marys < among cells:

the origin of the higher animals 404. vill

343 344 346 346

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