CONTENTS vii 



PAGES 



Chapter IV. THEORIES OF HEREDITY - - 50-80 



I. — THEORIES OF REPRODUCTION AND REGENERATION 50 



{a) spencer's PHYSIOLOGICAL UNITS - "51 



(b) Darwin's pangenesis - - - - 54 



(c) galton's stirp theory - - -55 



(d) weismann's germ-plasm - - - 57 



II. — THEORY OF MATURATION - - - - 64 



III. — THEORY OF FERTILIZATION - - - 68 



A. MIXING OF PARENTAL QUALITIES - - 69 



(a) BLENDED INHERITANCE - - -JO 



(&) EXCLUSIVE INHERITANCE - - - 72 



(c) PARTICULATE INHERITANCE - -73 



{d) INDIVIDUAL TRAITS - - - 74 



B. QUANTITATIVE CONTRIBUTION OF ANCESTORS - 75 

 IV. — THEORIES OF DEVELOPMENT - - -77 



{a) EVOLUTION V. EPIGENESIS - - -77 



{b) GERMINAL SELECTION - - - "79 



CHAPTER V. THEORIES OF HEREDITY (Co;z//w»f^) 81-92 



I, — REVERSION- - - - - - 81 



(a) TO GRANDPARENTS - - - - 8l 



(b) TO DISTANT ANCESTORS - - - 84 

 IL — TELEGONY - - - - - - 86 



III. — XENIA - - - - - - 87 



IV. — MATERNAL IMPRESSIONS - - - - 88 



V. — DETERMINATION OF SEX - - - - 89 



(fl) INFLUENCES OF FOOD AND OTHER AGENCIES - 90 



(6) INFLUENCE OF PARENTS - - - 90 



(c) INTERNAL CONDITIONS OF THE GERM - "91 



CHAPTER VI. THE INHERITANCE OF ACQUIRED 



CHARACTERS - - - 93-107 



I. — THEORETICAL CONSIDERATIONS - - "93 



II. — THE FACTS AND THEIR INTERPRETATION - "95 



(a) INHERITANCE IN UNICELLULAR ORGANISMS - 96 



{b) MUTILATIONS - - - - "97 



(c) CONGENITAL TRAITS - - - - 98 



{d) GERMINAL VARIATIONS - - - - 99 

 {e) ACQUIREMENTS ----- lOI 

 (/) ENVIRONMENTAL INFLUENCES ON GERM-CELLS- IO3 



(g) EXTERNAL OR SOCIAL INHERITANCE - - IO4 



III. — CONFUSION OF THE ISSUES - _ . 105 



(a) EVOLUTION AND DEVELOPMENT - - I05 



(6) LAMARCKISM V. NATURAL SELECTION - - 106 



