4 THE DAWN OF LIFE. 



ideas have been current in lectures and popular books, 

 and even in text-books, although to the minds of those 

 really acquainted with the facts, all the disputed points 

 have long ago been satisfactorily settled, and the true 

 nature and affinities of Eozoon are distinctly and 

 satisfactorily understood. 



This state of things has long ceased to be desirable 

 in the interests of science, since the settlement of the 

 questions raised is in the highest degree important to 

 the history of life. We cannot, it is true, affirm that 

 Eozoon is in reality the long sought prototype of ani- 

 mal existence; but it is for us at present the last 

 organic foothold, on which we can poise ourselves, that 

 we may look back into the abyss of the infinite past, 

 and forward to the long and varied progress of life in 

 geological time. Its consideration, therefore, is cer- 

 tain, if properly entered into, to be fruitful of interest- 

 ing and valuable thought, and to form the best possible 

 introduction to the history of life in connection with 

 geology. 



It is for these reasons, and because I have been 

 connected with this great discovery from the first, and 

 have for the last ten years given to it an amount of 

 labour and attention far greater than could be ade- 

 quately represented by short and technical papers, 

 that I have planned the present work. In it I propose 

 to give a popular, yet as far as possible accurate, ac- 

 count of all that is known of the Dawn-animal of the 

 Laurentian rocks of Canada. This will include, firstly : 

 a descriptive notice of the Laurentian formation itself. 



