166 THE POPULAR SCIENCE MONTHLY. 



lived to receive the just recognition of his services by the award of the 

 first Wollaston medal in 1831. 



But, although paleontology is a comparatively youthful scientific 

 specialty, the mass of materials with which it has to deal is already 

 prodigious. In the last fifty years the number of known fossil remains 

 of invertebrated animals has been trebled or quadrupled. The work 

 of interpretation of vertebrate fossils, the foundations of which were 

 so solidly laid by Cuvier, was earned on with wonderful vigor and 

 success by Agassiz in Switzerland, by Von Meyer in Germany, and, 

 last but not least, by Owen in this country, while, in later years, a mul- 

 titude of workers have labored in the same field. In many groups of 

 the animal kingdom the number of fossil forms already known is as 

 great as that of the existing species. In some cases it is much greater; 

 and there are entire orders of animals of the existence of which we 

 should know nothing except for the evidence afforded by fossil re- 

 mains. With all this it may be safely assumed that, at the present 

 moment, we are not acquainted with a tithe of the fossils which will 

 sooner or later be discovered. If we may judge by the profusion 

 yielded within the last few years by the Tertiary formations of North 

 America, there seems to be no limit to the multitude of mammalian 

 remains to be expected from that continent, and analogy leads us to 

 expect similar riches in Eastern Asia whenever the Tertiary formations 

 of that region are as carefully explored. Again, we have as yet almost 

 everything to learn respecting the terrestrial population of the Meso- 

 zoic epoch and it seems as if the Western Territories of the United 

 States were about to prove as instructive in regard to this point as 

 they have in respect of Tertiary life. My friend Professor Marsh 

 informs me that, within two years, remains of more than one hundred 

 and sixty distinct individuals of mammals, belonging to twenty species 

 and nine genera, have been found in a space not larger than the floor 

 of a good-sized room ; while beds of the same age have yielded three 

 hundred reptiles, varying in size from a length of sixty or eighty feet 

 to the dimensions of a rabbit. 



The task which I have set myself to-night is to endeavor to lay 

 before you, as briefly as possible, a sketch of the successive steps by 

 which our present knowledge of the facts of paleontology and of those 

 conclusions from them which are indisputable has been attained ; and 

 I beg leave to remind you at the outset that, in attempting to sketch 

 the progress of a branch of knowledge to which innumerable labors 

 have contributed, my business is rather with generalizations than with 

 details. It is my object to mark the epochs of paleontology, not to 

 recount all the events of its history. 



That which I just now called the fundamental problem of paleon- 

 tology, the question which has to be settled before any other can be 

 profitably discussed, is this : What is the nature of fossils ? Are they, 

 as the healthy common-sense of the ancient Greeks appears to have led 



