RECAPITULATION AND CONCLUSION 417 



plain evidence of the gradation and mutation of the forms of life? 

 Although geological research has undoubtedly revealed the former 

 existence of many links, bringing numerous forms of life much 

 closer together, it does not yield the infinitely m.any fine grada- 

 tions between past and present species required on the theory, and 

 this is the most obvious of the many objections which may be 

 urged against it. Why, again, do whole groups of allied species 

 appear, though this appearance is often false, to have come in 

 suddenly on the successive geological stages? Although we now 

 know that organic beings appeared on this globe, at a period in- 

 calculably remote, long before the lowest bed of the Cambrian 

 system was deposited, why do we not find beneath this system 

 great piles of strata stored with the remains of the progenitors of 

 the Cambrian fossils? For on the theory, such strata must some- 

 where have been deposited at these ancient and utterly unknown 

 epochs of the world's history. 



I can answer these questions and objections only on the sup- r 

 position that the geological record is far more imperfect than most / 

 geologists believe. The number of specimens in all our museums! 

 is absolutely as nothing compared with the countless generations 

 of countless species which have certainly existed. The parent form 

 of any two or more species would not be in all its characters di- 

 rectly intermediate between its modified offspring, any more than 

 the rock-pigeon is directly intermediate in crop and tail between 

 its descendants, the pouter and fantail pigeons. We should not 

 be able to recognize a species as the parent of another and modified 

 species, if we were to examine the two ever so closely, unless we 

 possessed most of the intermediate links; and owing to the im- 

 perfection of the geological record, we have no just right to expect 

 to find so many links. If two or three, or even more linking forms 

 were discovered, they would simply be ranked by many naturalists 

 as so many new species, more especially if found in different 

 geological sub-stages, let their differences be ever so slight. Nu- 

 merous existing doubtful forms could be named which are prob- 

 ably varieties; but who will pretend that in future ages so many 

 fossil links will be discovered, that naturalists will be able to de- 

 cide whether or not these doubtful forms ought to be called 

 varieties? Only a small portion of the world has bfn geologically 

 explored. Only organic beings of certain classes can be preserved 

 in a fossil condition, at least in any great number. Many species 

 when once formed never undergo any further change, but become 

 extinct without leaving modified descendants; and the periods 

 during which species have undergone modification, though long as 



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