Viil PREFACE 



The author was associated with the original discovery 

 and description of these supposed earliest traces of 

 life ; and has since, in the intervals of other work, 

 devoted much time to further exploration and research, 

 the results of which have been published from time to 

 time in the form of scientific papers. He has also 

 given attention to the later discoveries which have 

 tended to fill up the gap between the Laurentian fossil 

 and its oldest known successors. 



In 1875 he endeavoured to sum up in a popular form 

 what was then known, in a little volume named " The 

 Dawn of Life," which has long been out of print ; and 

 in 1893 the matter was referred to in a chapter of his 

 work " Salient Points in the Science of the Earth." 

 In 1895 he was invited to present the subject to a large 

 and intelligent audience in a course of lectures delivered 

 in the Lowell Institute, Boston ; and the success which 

 attended these lectures has induced him to reproduce 

 them in the present work, in the hope that inquiries 

 into the Dawn of Life may prove as fascinating to 

 general readers as to those who prosecute them as a 



