PREFACE. 



THE object of the following Chapters is to present a 

 sketch in outline of the World's Life-System tracing 

 from the earliest organisms in the stratified crust to 

 the forms that now adorn and people its surface. The 

 aim has been to link the remote to the recent the 

 living to the extinct that the general reader may be 

 enabled to form some intelligible conception of the 

 whole as a great and continuously-evolving scheme of 

 vegetable and animal existences. There is no attempt 

 whatever to teach anatomical details or point out spe- 

 cific distinctions the volume being intended not as a 

 Handbook of Palaeontology, but simply as a readable 

 sketch for the information of those who have neither 

 the time nor the preliminary training to avail them- 

 selves of works of higher scientific pretensions. And 

 yet the reader will find in these pages a reliable resumtf 

 of the science, as founded 011 the most recent discov- 

 eries, and a treatment of its bearings from a higher 

 stand-point than can be conveniently taken by the 

 mere text-books and manuals of Geology. At a time 



