504 ORIGIN OF SPECIES 



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 somewhere 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 

 supposition 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 cer- 

 tainly existed. The parent-form of any two or more species 

 would not be in all its characters directly intermediate be- 

 tween its modified offspring, any more than the rock-pigeon 

 is directly intermediate in crop and tail between its descend- 

 ants, the pouter and fantail pigeons. We should not be able 

 to recognise 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 imperfection 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. Numerous existing doubtful 

 forms could be named which are probably varieties ; but who 

 will pretend that in future ages so many fossil links will be 

 discovered, that naturalists will be able to decide whether or 

 not these doubtful forms ought to be called varieties? Only 

 a small portion of the world has been 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 be- 

 come extinct without leaving modified descendants ; and the 

 periods, during which species have undergone modification, 

 though long as measured by years, have probably been short 

 in comparison with the periods during which they retained 

 the same form. It is the dominant and widely ranging species 

 which vary most frequently and vary most, and varieties are 

 often at first local — both causes rendering the discovery of 



