Taking, then, evolution as a key to the mysteries of past life 

 on the earth, I invite your attention to the subject I have 

 chosen : THE INTRODUCTION AND SUCCESSION OF VERTEBRATE 

 LIFE IN AMERICA. 



In the brief hour allotted to me, I could hardly hope to give 

 more than a very incomplete sketch of what is now known on 

 this subject. I shall, therefore, pass rapidly over the lower 

 groups, and speak more particularly of the higher vertebrates, 

 which have an especial interest to us all, in so far as they 

 approach man in structure, and thus indicate his probable 

 origin. These higher vertebrates, moreover, are most important 

 witnesses of the past, since their superior organization made 

 them ready victims to slight climatic changes, which would 

 otherwise have remained unrecorded. 



In considering the ancient life of America, it is important to 

 bear in mind that I can only offer you a brief record of a few 

 of the countless forms that once occupied this continent. The 

 review I can bring before you will not be like that of a great 

 army, when regiment after regiment with full ranks moves by 

 in orderly succession, until the entire host has passed. My 

 review must be more like the roll-call after a battle, when only 

 a few scarred and crippled veterans remain to answer to their 

 names. Or rather, it must resemble an array of relics, dug 

 from the field of some old Trojan combat, long after the con- 

 test, when no survivor remains to tell the tale of the strife. 

 From such an ancient battle-field, a Schliernann might unearth 

 together the bronze shield, lance-head, and gilded helmet of a 

 prehistoric leader, and learn from them with certainty his race 

 and rank. Perhaps the skull might still retain the barbaric 

 stone weapon by which his northern foe had slain him. Near 

 by, the explorer might bring to light the commingled coat of 

 mail and trappings of a horse and rider, so strangely different 

 from the equipment of the chief, as to suggest a foreign ally. 

 From these, and from the more common implements of war 

 that fill the soil, the antiquary could determine, by patient 

 study, what nations fought, and, perhaps, when, and why. 



