XVI CONTENTS 



PARE 



(a) Sexual Affinity in general 301 



(6) More minute discussion of Sexual Affinity, and its 



different gradations ...... 305 



o. Self-fertilisation 306 



/3. Bastard Formation, or Hybridisation . . . 310 



7. The Influence of Environment upon Sexual Affinity 313 



5. Recapitulation and Attempted Explanations . . 316 



Literature , 320 



CHAPTER VIII. 



METABOLIC CHANGES OCCURRING BETWEEN PROTOPLASM, NUCLEUS AND CELL 



PRODUCTS . . ' . . 323 



I. Observations on the Position of the Nucleus, as an indication of its 



participation in Formative and Nutritive Processes . . . 324 



II. Experiments proving Reciprocal Action of Nucleus and Protoplasm 330 



Literature . 332 



CHAPTER IX. 



THE CELL AS THE ELEMENTARY GJSRM or AN ORGANISM. THEORIES OF 



HEREDITY 334 



I. History of the older Theories of Development .... 335 



II. More Recent Theories of Roproduction and Development . . 339 



III, The Nucleus as the Transmitter of Hereditary Elemental Germs . 344 



1. The Equivalence of the Male and Female Hereditary Masses 345 



2. The equal Distribution of the Multiplying Hereditary Mass 346 



3. The Prevention of the Summation of the Hereditary Mass . 350 



4. Isotropy of Protoplasm ....... 354 



IV. Development of the Elemental Germs 357 



Literature 361 



Index 363 



