CONTENTS 



VI. THE ORIGIN OF THE LAND VERTEBRATES. The 

 derivation of the pentadactyle limb. The deri- 

 vation of lungs. Air-breathing fishes. The 

 Dipnoi. The skull of the Dipnoi and the ac- 

 quisition of the auditory organ. The articulation 

 of the jaws . . . 92 



VII. THE RISE OF THE MAMMALIA. Peculiarities of 

 the Mammalia, Development and nourishment 

 of the embryo. The Placenta. Suckling and 

 Mammary glands. Milk-dentition. Peculiarities 

 of the Monotremes or Egg-laying Mammals. 

 Characteristics of the Marsupials. Their re- 

 productive peculiarities. The Marsupials as a 

 degenerate group 108 



VIII. REFLECTIONS ON THE PAST AND FUTURE OF ANIMAL 

 LIFE. Idea of evolution applied to modern man. 

 Inheritance of acquired characters. Possibility 

 of degeneration or standstill. Primitive man 

 and his gradual control of nature. Extinction 

 of wild animals in islands and on continents. 

 Gradual domestication of nature . . .136 



APPENDIX A. Classification of the chief Animal Phyla . 150 

 APPENDIX B. A Table of the chief Geological Epochs . 152 



INDEX 155 



O 



