206 WE AT IS LIFE 



Darwin himself pointed out: 



"But just in proportion as this process of ex- 

 termination had acted on an enormous scale, so 

 must the number of intermediate varieties, 

 which have formerly existed on the earth, be 

 truly enormous. Why then is not every geologi- 

 cal formation and every stratum full of such 

 intermediate links? Geology assuredly does not 

 reveal any such finely graduated organic change, 

 and this perhaps is the most obvious and gravest 

 objection which can be urged against my theory. 

 The explanation lies, so I believe, in the extreme 

 imperfection of the geological record. "^^ 

 But so far as the theory of descent is concerned, 

 the record of geology is as unsatisfactory today as 

 it was when Darwin wrote. Suess admitted some 

 years ago: "The fact remains that we do not find 

 species varying gradually within the limits of single 

 families or genera, and at different times. "^"^ (Surely, 

 no one would venture to suggest that the great geolo- 

 gist forgot the ^^Formenreihe" of Waagen^^ and the 

 change in the toes of the horse. ^*') 



2. The evident fixity of species, the evident ob- 

 served persistence of type, always has been a diffi- 



" The Origin of Species, Chapters IX and XII. 



1* The Face of the Earth, I, 13. 



" Die Formenreihe des Ammonites suhradiatiis. 



1' See Henry Fairfield Osborn, The Origin and Evolution of Life, 266-269. 



