| → forms, chiefly of plants, have spread widely throughout the world 1859 1860 1861 1866 |
| species have become widely spread 1869 1872 |
|
| → American 1859 1860 1861 1866 |
| belonging to American 1869 1872 |
|
| → given 1859 1860 1861 |
| allowed 1866 1872 |
| allowed many of 1869 |
|
| → general forms to the whole 1859 1860 1861 |
| fresh-water productions to prevail throughout the 1866 |
| species to prevail through large portions of the 1869 |
| forms to prevail throughout large portions of the 1872 |
|
| → some of the 1861 |
| the 1859 1860 1866 1869 1872 |
|
| → blind 1859 1860 1861 |
| character of most of the blind 1866 1869 1872 |
|
| → closely-allied 1860 1861 1866 |
| closely allied or 1859 1869 1872 |
|
| → showing, in accordance with the foregoing view, that at some former period there has been intercommunication or migration between the two regions. 1859 1860 1861 |
| showing, in accordance with the foregoing views, that at some former period there has been intercommunication or migration between the two regions. 1866 |
| and wherever many closely-allied species occur, there will be found many forms which some naturalists rank as distinct species, and others as mere varieties; these doubtful forms showing us the steps in the progress of modification. 1869 1872 |
|
| → under different physical conditions, 1859 1860 1861 1866 |
| OMIT 1869 1872 |
|
| → allied to it, 1859 1860 1861 1866 |
| OMIT 1869 1872 |
|