arge mass of facts, collected during the last few
decades, has confirmed this view, which in Darwin's time could only be
expressed with much reserve, and everyone knows that Darwin was always
very careful in statements of this kind.

From the same chapter I may here cite the following paragraph: "Thus
as I am inclined to believe, morphological differences,... such as
the arrangement of the leaves, the divisions of the flower or of the
ovarium, the position of the ovules, etc.--first appeared in many cases
as fluctuating variations, which sooner or later became constant through
the nature of the organism and of the surrounding conditions... but NOT
THROUGH NATURAL SELECTION (The italics are mine (H. de V.).); for as
these morphological characters do not affect the welfare of the species,
any slight deviation in them could not have been governed or accumulated
through this latter agency." ("Origin of Species" (6th edition), page
176.) We thus see that in Darwin's opinion, all small variations had
not the same importance. In favourable circumstances some could become
constant, but others could not.

Since the appearance of the first edition of "The Origin of Species"
fluctuating variability has been thoroughly studied by Quetelet. He
discovered the law, which governs all phenomena of organic life falling
under this head. It is a very simple law, and states that individual
variations follow the laws of probability. He proved it, in the first
place, for the size of the human body, using the measurements published
for Belgian recruits; he then extended it to various other measurements
of parts of the body, and finally concluded that it must be of universal
validity for all organic beings. It must hold true for all characters in
man, physical as well as intellectual and moral qualities; it must hold
true for the plant kingdom as well as for the animal kingdom; in short,
it must include the whole living world.

Quetelet's law may be most easily studied in those cases where the
variability relates to measure, number and weight, and a vast number of
facts have since confirmed its exactness and its validity for all kinds
of organisms, organs and qualities. But if we examine it more closely,
we find that it includes just those minute variations, which, as Darwin
repeatedly pointed out, have often no significance for the origin of
species. In the phenomena, described by Quetelet's law nothing "happens
to arise"; all is governed by