or highness.  We have also seen that, 
as the specialisation of parts and organs 
is an advantage to each being, so natural selection will tend 
to render the organisation of each being more specialised and perfect, and in this sense higher; not but that it may and will 
leave many creatures with simple and unimproved structures fitted for simple conditions of life, and in some cases will even degrade or simplify the organisation, yet leaving such degraded beings better fitted for their new walks of life. ↑| 2 blocks not present in  1861 1866 1869 1872; present in  1859 1860 |  |  There has been much discussion whether recent forms are more highly developed than ancient. 
I will not here enter on this subject, for naturalists have not as yet defined to each other's satisfaction what is meant by high and low forms. 
 |  
  
↑| 1 blocks not present in  1859 1860 1861 1866 1869 1872; present in  |  | 
 |  
   In a 
more general sense the more recent forms must, on my theory, be higher than the more ancient; for each 
new species is formed by having had some advantage 
in the struggle for life over other and preceding forms.  
If 
under a nearly similar climate, 
the eocene inhabitants of one quarter of 
the world were 
put into competition with the 
existing inhabitants 
of 
the same or some other quarter, the eocene fauna or flora would certainly 
be beaten and exterminated; 
as would a secondary fauna by an eocene, and a palæozoic fauna by a secondary fauna.  So that by this fundamental test of victory in the battle for life, as well as by the standard of the specialisation of organs, modern forms ought 
on the theory of natural selection 
to stand higher than ancient forms.  Is this the case?  A large majority of palæontologists would 
 certainly | certainly 1861 1866 |  certainly 1869 1872 |  
  
answer in the affirmative; 
 but in my judgment I cannot, after having read the discussions on this subject by Lyell, Bronn, and Hooker, look at this conclusion as fully proved, though highly probable. | but in my judgment I cannot, after having read the discussions on this subject by Lyell, Bronn, and Hooker, look at this conclusion as fully proved, though highly probable. 1866 |  
| but in my judgment I can, after having read the discussions on this subject by Lyell, and Hooker's views in regard to plants, concur only to a limited extent. 1861 |  
| and I suppose that the answer must be admitted as true, though difficult of full proof. 1869 |  
| and it seems that this answer must be admitted as true, though difficult of proof. 1872 |  
  
↑| 1 blocks not present in  1859 1860 1866 1869 1872; present in  1861 |  |  Nevertheless it may be anticipated that the evidence will be rendered more decisive by future geological research. 
 |  
   
 | 
 It is no valid objection to this 
 conclusion | conclusion 1866 |  | conclusion, 1869 1872 |  
  
 or to the general belief that species in the course of time change, | or to the general belief that species in the course of time change, 1866 |  
| OMIT 1869 1872 |  
  
that certain Brachiopods have been but slightly modified from an extremely remote geological 
 period, although no explanation can be given of this fact. | period, although no explanation can be given of this fact. 1866 |  
| epoch. 1869 |  
| epoch; and that certain land and fresh-water shells have remained nearly the same, from the time when, as far as is known, they first appeared. 1872 |  
   It is not an insuperable difficulty that Foraminifera have 
 not 
 progressed in organisation, | progressed in organisation, 1866 |  
| OMIT 1869 1872 |  
  
as insisted on by Dr. Carpenter, 
 since that most ancient of all epochs | since that most ancient of all epochs 1866 |  
| progressed in organisation since even 1869 1872 |  
  
the Laurentian 
 formation of Canada; | formation of Canada; 1866 |  
| epoch; 1869 1872 |  
  
for some organisms would have to remain fitted for simple conditions of life, and what 
 better | better 1866 |  
| could be better fitted 1869 1872 |  
  
for this end than these lowly organised Protozoa?  It is no great difficulty that 
 |