41G EECAl'ITULATION. Chap. XIV. 



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 incalculably 

 remote, long befc^re the lo^vest bed of the Cambrian system was 

 deix)sited, why do we not lind beneath this system great piles of 

 strata stored with the remains of the progenitors of the Cam- 

 brian fossils ? For on tlic theory such strata must somewhere 

 have been deposited at these ancient and utterly unknown 

 epochs in the world's history. 



I can answer these ciuestions and olijcctions only on the 

 supposition that the geological record is far more imperfect 

 than most geologists believe. The number of s]x;cimens in all 

 our museums is absolutely as nothing compared with the 

 countless generations of countless species wliich have certainly 

 existed. The parent-form of any two or more sjx^cies would 

 not be in all its characters directly intermediate between its 

 modified odspring, any more than the rock-pigeon is directly 

 intermediate in crop and tail between its descendants the 

 pouter and fantail pigeons. We should not l>e able to recog- 

 nize a species as the parent of another and modified species, if 

 we were to examine both ever so closely, unless we possessed 

 most of the intermediate links ; and owing to the imjxjrfection 

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

 find so many hnks. If two or three, or even more linking 

 forms were discovered, they would simply be ranked as so 

 many new species, more especially if found in different geolo- 

 gical 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 

 man}- fossil links Avill 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 

 i\uinl)er. Many species when once formed never undergo any 

 further change, but become extinct without leaving modified 

 descendants ; and the periods, during which species have un- 

 dergone modification, though long as measured by years, have 

 ])r()l)ably been short in comparison with the periods during 

 which tliey have retained the same fonn. It is the dominant 

 and widely-ranging species which vary most frequently anil vary 

 most, and varieties are often at first local — both clauses render- 

 ing the discovery of intermediate links in any one formation 



