which it did not subsist in its natural state. It is an error to speak of
man "tampering with nature" and causing variability. If a man drops a piece
of iron into sulphuric acid, it cannot be said strictly that he makes the
sulphate of iron, he only allows their elective affinities to come into
play. If organic beings had not possessed an inherent tendency to vary, man
could have done nothing. (Introduction/2. M. Pouchet has recently
('Plurality of Races' English Translation 1864 page 83 etc.) insisted that
variation under domestication throws no light on the natural modification
of species. I cannot perceive the force of his arguments, or, to speak more
accurately, of his assertions to this effect.) He unintentionally exposes
his animals and plants to various conditions of life, and variability
supervenes, which he cannot even prevent or check. Consider the simple case
of a plant which has been cultivated during a long time in its native
country, and which consequently has not been subjected to any change of
climate. It has been protected to a certain extent from the competing roots
of plants of other kinds; it has generally been grown in manured soil; but
probably not richer than that of many an alluvial flat; and lastly, it has
been exposed to changes in its conditions, being grown sometimes in one
district and sometimes in another, in different soils. Under such
circumstances, scarcely a plant can be named, though cultivated in the
rudest manner, which has not given birth to several varieties. It can
hardly be maintained that during the many changes which this earth has
undergone, and during the natural migrations of plants from one land or
island to another, tenanted by different species, that such plants will not
often have been subjected to changes in their conditions analogous to those
which almost inevitably cause cultivated plants to vary. No doubt man
selects varying individuals, sows their seeds, and again selects their
varying offspring. But the initial variation on which man works, and
without which he can do nothing, is caused by slight changes in the
conditions of life, which must often have occurred under nature. Man,