HOW LIFE APPEARED ON EARTH 135 



cruliar traveling powers or habits of life." 8 That 

 higher classes are descended from these is there- 

 fore "in no single case other than probable," or 

 as Darwin says in the words previously quoted, 

 we cannot prove the evolution of even one single 

 species into another. 9 The word species must, as 

 further stated, be taken in the strict sense in which 

 Darwin there, understands it, and not as a mere 

 variety. The same concession, we also saw, was 

 made by M. Yves Delage of the Sarbonne, and 

 other leading evolutionists. 



The distinct species, in other words, every- 

 where appear suddenly. The transitions traced 

 in science primers, are often merely apparent and 

 it is found, as in the stock example of the horse, 

 that the beautiful gradational forms usually pic- 

 tured for the instant conviction of the unsophisti- 

 cated student could not possibly have succeeded 

 one another. The following authoritative pas- 

 sage from A. Sedgwick, dealing with this classic 

 example, which was long regarded as the triumph 

 of evolution, in so much as this was based upon 

 the supposed evidence of intermediate links, de- 

 serves to be repeated here: 



So far as the characters mentioned are concerned, we have 

 a very remarkable series of forms which at first sight appear 

 to constitute a linear series with no cross connections. 

 Whether, however, they really do this is a difficult point to 



Steinmann, "Die geologischen Grundlagen der Abttam- 

 mungslehre," p. 233. (Frank p. 33.) 

 "'Life and Letters of Charles Darwin," I, p. 210. 



