| → vary at all in the several 1859 1860 1861 1866 | 
| present individual differences in all 1869 | 
| present individual differences in almost every 1872 | 
  | 
| → the high geometrical ratio 1860 1861 1866 1869 | 
| the high geometrical powers 1859 | 
| their geometrical rate 1872 | 
  | 
| → of each species, 1859 1860 1861 1866 1869 | 
| a severe struggle for life 1872 | 
  | 
| → a severe struggle for life at some age, season, or year, 1860 1861 1866 1869 | 
| at some age, season, or year, a severe struggle for life, 1859 | 
| at some age, season, or year, 1872 | 
  | 
| → preservation, 1859 1860 1869 | 
| preservation 1861 1866 | 
| pre- servation, or the survival of the fittest, 1872 | 
  | 
| → I 1859 1860 1861 1866 1872 | 
| or the survival of the fittest, I 1869 | 
  | 
| → for the sake of brevity, 1859 1860 1861 1866 | 
| OMIT 1869 1872 | 
  | 
| → 
Selection; and it leads to the improvement of each creature in relation to its organic and inorganic conditions of life.
 1860 | 
| Selection. 1859 1861 1866 1869 1872 | 
  | 
| ↑ 1 blocks not present in  1859 1860 1869; present in  1861 1866 1872 | 
|  It leads to the improvement of each creature in relation to its organic and inorganic conditions of life; and consequently, in most cases, to what must be regarded as an advance in organisation. 
 | 
  | 
| → with 1859 1860 1861 1866 | 
| or rivalry with 1872 | 
  | 
| → males. 1859 1860 1861 1866 | 
| males; and these characters will be transmitted to one sex or to both sexes, according to the form of inheritance which prevails. 1872 | 
  | 
| → nature, in modifying and 1859 1860 1861 1866 | 
| OMIT 1869 1872 | 
  |