Origin of Species Variorum

→ genera now living in the United 1869 1872

genera of these 1859 1860

endemic genera of the United 1861

genera naturally living in the United 1866

→ struggled 1859 1860 1861 1866 1869

in any country struggled 1872

→ of any country, 1859 1860 1861 1866 1869

OMIT 1872

→ in 1859 1860 1861 1866 1869

of structure in 1872

have been expected that the plants which

have

would

succeeded

succeed

in becoming naturalised in any land would generally have been closely allied to the indigenes; for these are commonly looked at as specially created and adapted for their own country. It

might,

might

also,

perhaps

perhaps,

have been expected that naturalised plants would have belonged to a few groups more especially adapted to certain stations in their new homes. But the case is very different; and Alph.

Candolle has well

remarked,

remarked

in his great and admirable work, that floras gain by naturalisation, proportionally with the number of the native genera and species, far more in new genera than in new species. To give a single instance: in the last edition of Dr. Asa

Grays

Gray's

Manual

'Manual

of the Flora of the Northern United

States,

States,'

260 naturalised plants are enumerated, and these belong to 162 genera. We thus see that these naturalised plants are of a highly diversified nature. They differ, moreover, to a large

extent

extent,

from the indigenes, for out of the 162

genera,

naturalised genera,

no less than 100 genera are not there indigenous, and thus a large proportional addition is made to the →genera now living in the United States.

By considering the nature of the plants or animals which have →struggled successfully with the

indigenes,

indigenes

→of any country, and have there become naturalised, we

can

may