"Thus, as I am inclined to believe, morphological differences, which we consider as important--such as the arrangement of the leaves, the divisions of the flower or of the ovarium, the position of the ovules, &c.--_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, as well as through the intercrossing of distinct individuals, _but not through natural selection_; for as these morphological characters do not affect the welfare of the _species_, any slight deviations in them could not have been governed or accumulated through this latter agency. It is a strange result which we thus arrive at, namely, that characters of slight vital importance to the _species_, are the most important to the systematist; but, as we shall hereafter see when we treat of the genetic principle of classification, this is by no means so paradoxical as it may at first appear[162]."
Clearly the view here expressed is that characters which are now distinctive of higher taxonomic divisions "first appeared" in the parent species of such divisions; for not only would it be unreasonable to attribute the rise and preservation of useless characters to "fluctuating variations" affecting a number of species or genera similarly and simultaneously; but it would be impossible that, if such were the case, they could be rendered "constant through the nature of the organism and of the surrounding conditions, as well as through the intercrossing of distinct individuals[163]."
[163] The passage to which these remarks apply is likewise quoted, in the same connexion as above, in my paper on _Physiological Selection_. In criticising that paper in _Nature_ (vol. xxxix. p. 127), Mr. Thiselton Dyer says of my interpretation of this passage, "the obvious drift of this does not relate to specific differences, but to those which are characteristic of family." But in making this remark Mr. Dyer could not have read the passage with sufficient care to note the points which I have now explained.
Here is another passage to the same general effect. In alluding to the objection from inutility as advanced by Bronn, Broca, and Nägeli, Mr. Darwin says:--"There is much force in the above objection"; and, after again pointing out the important possibility in any particular cases of hidden or former use, and the action of the laws of growth, he goes on to say,--"In the third place, we have to allow for the direct and definite action of changed conditions of life, and for so-called spontaneous variations, in which the nature of the conditions plays quite a subordinate part[164]." Elsewhere he says,--"It appears that I formerly underrated the frequency and value of these latter forms of variation as leading to permanent modifications of structure _independently of natural selection_[165]." The "forms of variation" to which he here alludes are "variations which seem to us in our ignorance to arise spontaneously"; and it is evident that such variations cannot well "arise" in two or more species of a genus similarly and simultaneously, so as independently to lead "to permanent modifications of structure" in two or more parallel lines. It is further evident that by "spontaneous variations" Darwin alludes to extreme cases of spontaneous departure from the general average of specific characters; and therefore that lesser or more ordinary departures must be of still greater "frequency."