Origin of Species Variorum

Comparison with 1869

Umbelliferæ these differences are of such apparent importance — the seeds being sometimes orthospermous in the exterior flowers and cœlospermous in the central flowers, — that the elder De Candolle founded his main divisions in the order on such characters. Hence, as before remarked, we see that modifications of structure, viewed by systematists as of high value, may be wholly due to the laws of variation and correlation, without being, as far as we can judge, of the slightest service to the species.

We may often falsely attribute to correlated variation structures which are common to whole groups of species, and which in truth are simply due to inheritance; for an ancient progenitor may have acquired through natural selection some one modification in structure, and, after thousands of generations, some other and independent modification; and these two modifications, having been transmitted to a whole group of descendants with diverse habits, would naturally be thought to be correlated in some necessary manner. Some correlations are apparently due to the manner in which natural selection acts. ↑ For instance, Alph. De Candolle has remarked that winged seeds are never found in fruits which do not open: I should explain this rule by the impossibility of seeds gradually becoming winged through natural selection, unless the capsules first opened themselves; for in this case alone could the seeds, which were a little better adapted to be wafted by the wind, gain an advantage over those less well fitted for wide dispersal.

Compensation and Economy of Growth .

The elder Geoffroy and Goethe propounded, at about the same period, their law of compensation or balancement of growth; or, as Goethe expressed it, "in order

Umbelliferæ these differences are of such apparent importance— the seeds being in some cases, according to Tausch, orthospermous in the exterior flowers and cœlospermous in the central flowers,— that the elder De Candolle founded his main divisions of the order on analogous differences. Hence we see that modifications of structure, viewed by systematists as of high value, may be wholly due to unknown laws of correlated growth, and without being, as far as we can see, of the slightest service to the species.

We may often falsely attribute to correlation of growth structures which are common to whole groups of species, and which in truth are simply due to inheritance; for an ancient progenitor may have acquired through natural selection some one modification in structure, and, after thousands of generations, some other and independent modification; and these two modifications, having been transmitted to a whole group of descendants with diverse habits, would naturally be thought to be correlated in some necessary manner. ↑ So, again, some correlations, occurring throughout whole orders, are apparently due to the manner alone in which natural selection can act. For instance, Alph. de Candolle has remarked that winged seeds are never found in fruits which do not open: I should explain the rule by the fact that seeds could not gradually become winged through natural selection, except in fruits which opened; so that the individual plants producing seeds which were a little better fitted to be wafted further, might get an advantage over those producing seed less fitted for dispersal; and this process could not possibly go on in fruit which did not open. ↑

The elder Geoffroy and Goethe propounded, at about the same period, their law of compensation or balancement of growth; or, as Goethe expressed it, "in order