204. WHAT IS LIFE 



of Nature appear together, and together disappear."^ 

 Suess, of course, like all other geologists of today, 

 believes in the unbroken ascent, or evolution, of life, 

 but he testifies to "... . the simultaneous appear- 

 ance and disappearance over vast areas of whole 

 communities, of whole economic unities; the same 

 phenomenon which Heer long ago happily designated 

 'the periodical recoinage of organisms'."^ 



The older geologists, interpreting the evidence of 

 the geologic record unhampered by any difficulty of 

 theory, formed their estimate of the plural origins 

 of life. Creation was the method assumed. Hence 

 they were not concerned about the fact that these 

 great geological epochs of appearance, disappearance, 

 and new appearance of life would seem to indicate 

 plural origins. They had only to say what they saw, 

 without having to reconcile it with any theory. 



This represents the general position of pre-Dar- 

 winian geologists; though some geologists indeed 

 occupied themselves much with the problem of life 

 as related to evolution. With Suess: "Let us glance 

 over the period from 1849 to 1859. The doctrine of 

 successive creations reigns everywhere. Each larger 

 subdivision of the geological series is considered to 

 denote an act of special creation."^" 



» The Face of the Earth, I, 11. 

 8 Ibid., 13. 

 '» Ibid., 8. 



