Vlll CONTENTS. 



parison of Artificial with Natural Conditions of Breeding. — The 

 Struggle for Existence. — Necessary Application of the Theory of 

 Descent to Man. — Descent of Man from the Ape. — Thomas Hux- 

 ley. — Karl Vogt. — Friedrich Rolle. — The Pedigrees in the Oenerelle 

 Morphologie and the " History of Creation." — The Genealogical 

 Alternative. — The Descent of Man from Apes deduced from the 

 Theory of Descent. — The Theory of Descent as the Greatest Induc- 

 tive Law of Biology. — Foundation of this Induction. — Palaeon- 

 tology. — Comparative Anatomy. — The Theory of Rudimentary 

 Organs. — Purposelessness, or Dysteleology. — Genealogy of the 

 Natural System. — Chorology. — GSkology. — Ontogeny. — Refutation 

 of the Dogma of Species. — The " Monograph on the Chalk 

 Sponges j " Analytic Evidence for the Theory of Descent ... 98 



CHAPTER VI. 



THE EGG-CELL AND THE AMCEBA. 



The Egg of Man and of other Animals is a Simple Cell. — Import and 

 Essential Principles of the Cell Theory. — Protoplasm (Cell-sub. 

 stance), and the Nucleus (Cell-kernel), as the Two Essential Con- 

 stituent Parts of every Genuine Cell. — The Undifferentiated Egg- 

 cell, compared with a highly Differentiated Mind-cell or Nerve-cell 

 of the Brain. — The Cell as an Elementary Organism, or an Indi- 

 vidual of the First Order.— The Phenomena of its Life. — The 

 Special Constitution of the Egg-cell. — Yelk. — The Germ-vesicle. — 

 The Germ-spot. — The Egg-membrane, or Chorion. — Application of 

 the Fundamental Principle of Biogeny to the Egg-cell. — One-celled 

 Organisms. — The Amoebae. — Organization and Vital Phenomena. — 

 Their Movements. — Amoeboid Cells in Many-celled Organisms. — 

 Movements of such Cells, and Absorption of Solid Matter. — Absor. 

 bent Blood Corpuscles. — Comparison of Amoeba with Egg-cell. — 

 Amoeboid Egg-cells of Sponges. — The Amoeba as the Common 

 Ancestral Form of Many-celled Organisms ... ... ... 120 



CHAPTER VII. 



THE PROCESSES OF EVOLUTION AND IMPREGNATION. 



Development of the Many-celled from the One-celled Organism. — The 

 Cell-hermit and the Cell-state. — The Principles of the Formation 

 of the State. — The Differentiation of the Individuals as the 



