FOSSIL PEDIGREES 125 



only say that such persons cannot have a very high or exact- 

 ing conception of what scientific certainty really means. 



For the rest, it cannot even be said that the palaeontological 

 record furnishes good circumstantial evidence that our globe 

 has been the scene of a process of organic evolution. In fact, 

 so utterly at variance with this view is the total impression 

 conveyed by the visible portion of the geological column, that 

 the modern geologist proposes, as we have seen, to probe 

 depths beneath its lowest strata for traces of that alleged 

 transmutation, which higher horizons do not reveal. There are 

 six to eight thick terranes below the Cambrian, we are told, 

 and igneous masses that were formerly supposed to be basal 

 have turned out to be intrusions into sedimentary accumula- 

 tions, all of which, of course, is fortunate for the theory of 

 organic evolution, as furnishing it with a sadly needed new 

 court of appeal. The bottom, so to speak, has dropped out of 

 the geological column, and Prof. T. C. Chamberlin announces 

 the fact as follows: ''The sharp division into two parts, a life- 

 less igneous base and a sedimentary fossiliferous superstruc- 

 ture, has given place to the general concept of continuity with 

 merely minor oscillations in times and regions of major activ- 

 ity. Life has been traced much below the Cambrian, but its 

 record is very imperfect. The recent discoveries of more ample 

 and varied life in the lower Palaeozoic, particularly the Cam- 

 brian, implies, under current evolutional philosophy, a very 

 great downward extension of life. In the judgment of some 

 biologists and geologists, this extension probably reaches below 

 all the pre-Cambrian terranes as yet recognized, though this 

 pre-Cambrian extension is great. ^ The 'Azoic' bottom has re- 

 tired to depths unknown. This profoundly changes the life 

 aspect of the 'column.' " {Science, Feb. 8, 1924, p. 128.) All this 

 is doubtless true, but such an appeal, from the known to the 

 unknown, from the actual to the possible, is not far-removed 

 from a confession of scientific insolvency. Life must, of course, 

 have had an earlier history than that recorded in the pre- 

 Cambrian rocks. But even supposing that some portion of an 



