| Comparison with 1861 | 
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| Text in this page (from  paragraph 3701, sentence 400, word 2 to  paragraph 3701, sentence 700, word 37) is not present in 1861 | 
The problem 
 is | is 1861 |  
| whether organisation on the whole has advanced is 1866 1869 1872 |  
  
in many ways excessively intricate.  The geological record, at all times imperfect, does not extend far enough back, as I believe, 
to show with unmistakeable clearness that within the known history of the world organisation has largely advanced.  Even at the present day, looking to members of the same class, naturalists are not unanimous which forms are 
 highest: | highest: 1861 1872 |  
| to be ranked as highest: 1866 1869 |  
  
thus, some look at the selaceans or 
 sharks | sharks 1861 |  | sharks, 1866 1869 1872 |  
  
from their approach in some important points of structure to 
 reptiles | reptiles 1861 |  | reptiles, 1866 1869 1872 |  
  
as the highest fish; others look at the teleosteans as the highest.  The ganoids stand intermediate 
between the selaceans and teleosteans; the latter at the present day are largely preponderant in number; but formerly selaceans and ganoids alone existed; and in this case, according to the standard of highness chosen, so will it be said that fishes have 
 | 
 
  
  
objections as the above would be fatal to 
 any 
 view 
 which | which 1866 1869 |  | if it 1872 |  
  
included advance in organisation as a necessary contingent.  They would 
 be fatal to my view if | be fatal to my view if 1866 |  
| likewise be fatal to my view if 1869 |  
| likewise be fatal, if the above 1872 |  
  
Foraminifera, for instance, could be proved to have first come into existence during the Laurentian epoch, or 
 Brachiopods | Brachiopods 1866 1869 |  
| the above Brachiopods 1872 |  
  
during the 
 lower Silurian | lower Silurian 1866 |  | Cambrian 1869 1872 |  
  
 formations; | formations; 1866 |  | formation; 1869 1872 |  
  
for 
 if 
this 
 were proved, | were proved, 1866 |  | case, 1869 1872 |  
  
there would not have been time sufficient for the development of these organisms up to the standard which they 
 had 
then reached.  When 
 once 
advanced up to any given point, there is no 
 necessity | necessity 1866 1869 |  | necessity, 1872 |  
  
on the theory of natural 
 selection | selection 1866 1869 |  | selection, 1872 |  
  
for their further continued progress; though they will, during each successive age, have to be slightly modified, so as to hold their places in relation to 
 their changing conditions of life. | their changing conditions of life. 1866 |  
| the changing conditions of life. 1869 |  
| slight changes in their conditions. 1872 |  
   
 All such | All such 1866 1869 |  | The foregoing 1872 |  
  
objections hinge on the question whether we 
 have any sufficient knowledge of the antiquity of | have any sufficient knowledge of the antiquity of 1866 |  
| really know how old 1869 1872 |  
  
the world 
 and of the periods when | and of the periods when 1866 |  
| is, and at what periods 1869 |  
| is, and at what period 1872 |  
  
the various forms of life first appeared; and this may 
 be boldly | be boldly 1866 |  | be 1869 |  | well be 1872 |  
  
disputed.  | 
 | 
 The problem 
 whether organisation on the whole has advanced is | whether organisation on the whole has advanced is 1866 1869 1872 |  
| is 1861 |  
  
in many ways excessively intricate.  The geological record, at all times imperfect, does not extend far enough back, 
 as I believe, | as I believe, 1861 1866 1869 |  
| OMIT 1872 |  
  
to show with unmistakeable clearness that within the known history of the world organisation has largely advanced.  Even at the present day, looking to members of the same class, naturalists are not unanimous which forms 
 are | are 1861 1866 1869 |  
| ought to be ranked as 1872 |  
  
 to be ranked as highest: | to be ranked as highest: 1866 1869 |  
| highest: 1861 1872 |  
  
thus, some look at the selaceans or 
 sharks, | sharks, 1866 1869 1872 |  | sharks 1861 |  
  
from their approach in some important points of structure to 
 reptiles, | reptiles, 1866 1869 1872 |  | reptiles 1861 |  
  
as the highest fish; others look at the teleosteans as the highest.  The ganoids stand 
 intermediate | intermediate 1861 1866 1872 |  | in- termediate 1869 |  
  
between the selaceans and teleosteans; the latter at the present day are largely preponderant in number; but formerly selaceans and ganoids alone existed; and in this case, according to the standard of highness chosen, so will it be said that fishes have 
 |