xviii THE EARTH BEFORE HISTORY 



Each volume will contain a Bibliography : not exhaustive, 

 of course, but sufficiently complete to furnish students with the 

 necessary data for obtaining additional information. The works 

 mentioned in this Bibliography will be numbered ; and in the 

 notes references will be made as far as possible by means of 

 numbers — one for the bibliographical item, one for the volume 

 of the work, and, if necessary, a number for the page. Placed 

 one after another, and separated simply by commas, these 

 references can be multiplied without encroaching upon or 

 encumbering the book itself. 



By this means we shall be able to realize our double purpose 

 of satisfying the demands of science and helping the student, 

 and of addressing ourselves, at the same time, to the large 

 cultivated public interested in human destinies. The presenta- 

 tion of the results attained in language as clear and as vivid 

 as possible will occupy the bulk of the pages. The amateur in 

 history will find an advantage in this : he will even escape the 

 involuntary distraction produced by notes which are immediate' y 

 intelligible. In order to be useful our numbered references will 

 necessitate a study of the Bibliography ; but the author will thus 

 be able, in an economical manner, to justify the essential parts 

 of his text, and the historically minded reader, if he so desires, 

 to considt the sources with a minimum of effort, whether in order 

 to verify the contents or to extend the work beyond the point 

 where the author has left it. 



Works without references, syntheses where, at the best, the 

 Bibliography is found at the beginning or at the end of the 

 chapters, without running notes, are quite popular to-day, in 

 Germany and elsewhere, and represent a reaction against the 

 abuse of erudite annotation. But this opposite excess appears 

 to us also dangerous. Under such anti-scientific conditions we 

 are forced to take the author at his word. But no matter how 

 scrupulous he may be, an author will often allow himself to group 

 facts artificially, to present hypotheses as certitudes. As far as 

 facts or the explanation of facts are concerned, the certain, the 

 probable, the possible ought, of course, to be carefully graded and 

 be so offered for criticism. 



The bearings of each work and what still remains to be done 

 will be touched on in the last chapter of every volume in an 

 arresting manner. The object aimed at will be to show the lacunce 

 still existing, the questions which arise in the various fields in 



