CONTENTS OF VOL. II. 



Lia*. of Plates x 



List of Woodcuts 



List of Genetic Tables xvii 



CHAPTER XV. 



THE DURATION OF HUMAN TRIBAL HISTORY. 



Comparison of Ontogenetic and Phylogenetic Periods of Time. Dora- 

 tion of Germ -history in Man and in Different Animals. Extreme 

 Brevity of the Latter in Comparison with the Immeasurable Long 

 Perioda of Tribal Histoiy. Relation of this Rapid Ontogenetio 

 Modification to the Slow Phylogenetic Metamorphosis. Estimate 

 of the Past Duration of the Organic World, founded on the Relative 

 Thickness of Sedimentary Rock-strata, or Neptunian Formations. 

 The Five Main Divisions in the Latter : I. Primordial, or 

 Archilithic Epoch. II. Primary, or Palaeolithic Epoch. III. Second- 

 ary, or Mesolithic Epoch. IV. Tertiary, or Caenolithic Epoch. 

 V. Quaternary, or Anthropolithic Epoch. The Relative Duration 

 of the Five Epochs. The Results of Comparative Philology as 

 Explaining the Phylogeny of Species. The Inter-relations of the 

 Main Stems and Branches of the Indo-Germanio Languages are 

 Analogous to the Inter-relations of the Main Stems and Branches 

 of the Vertebrate Tribe. The Parent Forms in both Cases are 

 Extinct. The Most Important Stages among the Human An- 

 cestral Forms. Monera originated by Spontaneous Generation. 

 Necessity of Spontaneous Generation ... ... 



