5 1 4 THE POPULAR SCIENCE MONTHLY. 



I shall, therefore, pass rapidly over the lower groups, and speak more 

 particularly of the higher vertebrates, which have an especial interest 

 for us all, in so far as they approach man in structure, and thus indi- 

 cate 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 oth- 

 erwise 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 count- 

 less forms that once occupied this continent. The review I can bring 

 before you will not be like that of a great army, wdien 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 an- 

 swer to their names. Or, rather, it must resemble an array of relics, 

 dug from the field of some old Trojan combat, long after the contest, 

 when no survivor remains to tell the tale of the strife. From such an 

 ancient battle-field, a Schliemann 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. 



By this same method of research the more ancient strata of the 

 earth have been explored, and in our Western wilds veritable battle* 

 fields, strewed with the fossil skeletons of the slain, and guarded 

 faithfully by savage superstition, have been despoiled, yielding to 

 science treasures more rare than bronze or gold. "Without such spoils, 

 from many fields, I could not have chosen the present theme for my 

 address to-nis;ht. 



*& 



According to present knowledge, no vertebrate life is known to 

 have existed on this continent in the Archaean, Cambrian, or Silurian 

 period; yet during this time more than half of the thickness of 

 American stratified rocks was deposited. It by no means follows that 

 vertebrate animals of some kind did not exist here in those remote 

 ages. Fishes are known from the Upper Silurian of Europe, and 

 there is every probability that they will yet be discovered in our 

 strata of the same age, if not at a still lower horizon. 



In the shore-deposits of the early Devonian sea, known as the 

 Schoharie Grit, characteristic remains of fishes were preserved, and in 

 the deeper sea that followed, in which the Corniferous limestone was 



