natural selection," at the same time cutting out the word
"accidental."

It may perhaps make the workings of Mr. Darwin's mind clearer to the
reader if I give the various readings of this passage as taken from
the three most important editions of the "Origin of Species."

In 1859 it stood, "Further, we must suppose that there is a power
always intently watching each slight accidental alteration," &c.

In 1861 it stood, "Further, we must suppose that there is a power
(natural selection) always intently watching each slight accidental
alteration," &c.

And in 1869, "Further, we must suppose that there is a power
represented by natural selection or the survival of the fittest
always intently watching each slight alteration," &c. {94a}

The hesitating feeble gait of one who fears a pitfall at every step,
so easily recognisable in the "numerous, successive, slight
alterations" in the foregoing passage, may be traced in many another
page of the "Origin of Species" by those who will be at the trouble
of comparing the several editions. It is only when this is done,
and the working of Mr. Darwin's mind can be seen as though it were
the twitchings of a dog's nose, that any idea can be formed of the
difficulty in which he found himself involved by his initial blunder
of thinking he had got a distinctive feature which entitled him to
claim the theory of evolution as an original idea of his own. He
found his natural selection hang round his neck like a millstone.
There is hardly a page in the "Origin of Species" in which traces of