Incompleteness of the Geological Record 33 



we can accept as fact. This sound principle thus estabHshed 

 by Cuvier did not show him that transformation of species 

 had taken place. Yet it must be clear that unless a succession 

 of species were established, we could not today confidently 

 uphold the doctrine of evolution. Here Cuvier, an opponent 

 of the idea of evolution of living forms, helped to lay the 

 foundation for the idea — as we shall see later, he did the 

 same in another important corner. 



Incovtpleteness of the Geological Record 



In order to make the fossils show that, in addition to 

 a succession of species, there was also continuity of life, it 

 would be necessary to find a complete, continuous series of 

 species from the ancient forms to those now living. Such 

 continuity of fossil forms does not exist, except in scattered 

 instances. Before considering these we should first ask our- 

 selves whether it is reasonable to expect such complete series. 

 Take the life of man upon earth within historic times. In 

 how many families would it be possible to point to the mia- 

 terial remains of half a dozen generations of direct ancestors? 

 Of the millions of people who have died within a century, 

 how many have left any material remains whatever, to say 

 nothing of recognizable skeletons? 



The conditions under which fossil remains are to be ex- 

 pected are rather restricted, so that for many forms that 

 may have existed upon the earth we can expect no repre- 

 sentative relics at all. There are the many species of micro- 

 scopic plants and animals which have no hard parts that 

 could be preserved. If they existed in past ages we can see 

 today only such evidence of their activities as the decayed 

 remains of larger plants and animals, since we now know 

 that the decay was due to the feeding and fermenting proc- 

 esses of microorganisms. At any rate we know that today 

 decay is due only to such processes. Then there are the ani- 

 mals whose fossil remains are buried under the bed of the 

 sea, quite inaccessible, and likely to remain so at least for 



