334 DARWINISM STATED BY DARWIN HIMSELF. 



time for their accumulation, are entirely destitute of 

 organic remains, without our being able to assign any 

 reason ; one of the most striking instances is that of the 

 Plysch formation, which consists of shale and sandstone, 

 several thousand, occasionally even six thousand, feet in 

 thickness, and extending for at least three hundred miles 

 from Vienna to Switzerland; and, although this great 

 mass has been most carefully searched, no fossils, except 

 a few vegetable remains, have been found. 



WIDE INTERVALS OF TIME BETWEEN THE GEOLOGICAL 

 FORMATIONS. 



Pa 271 ^^^ *^^ imperfection in the geological 

 record largely results from another and more 

 important cause than any of the foregoing; namely, 

 from the several formations being separated from each 

 other by wide intervals of time. This doctrine has been 

 emphatically admitted by many geologists and paleon- 

 tologists, who, like E, Forbes, entirely disbelieve in the 

 change of species. When we see the formations tabulated 

 in written works, or when we follow them in nature, it 

 is diflBcult to avoid believing that they are closely con- 

 secutive. But we know, for instance, from Sir K. Mur- 

 chison's great work on Eussia, what wide gaps there are 

 in that country between the superimposed formations ; 

 so it is in North America, and in many other parts of 

 the world. The most skillful geologist, if his attention 

 had been confined exclusively to these large territories, 

 would never have suspected that, during the periods 

 which were blank and barren in his own country, great 

 piles of sediment, charged with new and peculiar forms 

 of life, had elsewhere been accumulated. And if, in each 

 separate territory, hardly any idea can be formed of the 



