says their generic importance, "like that of all their parts, not only in
this, | this, 1861 1866 1872 | | this 1859 1860 |
| Again, 1866 1872 | | Again 1859 1860 1861 |
| insects: 1866 1872 | | insects, 1859 1860 1861 |
| much 1866 | | much, 1859 1860 1861 1872 |
| probably 1859 1860 1861 1866 | probably 1872 |
| 7 blocks not present in 1859 1860 1861 1866 1872; present in 1869 | | That the mere physiological importance of an organ does not determine its classificatory value, is almost proved by the fact, that in allied groups, in which the same organ, as we have every reason to suppose, has nearly the same physiological value, its classificatory value is widely different.
No naturalist can have worked at any group without being struck with this fact; and it has been fully acknowledged in the writings of almost every author.
It will suffice to quote the highest authority, Robert Brown, who, in speaking of certain organs in the Proteaceæ, says their generic importance, "like that of all their parts, not only in this, but, as I apprehend, in every natural family, is very unequal, and in some cases seems to be entirely lost."
Again, in another work he says, the genera of the Connaraceæ "differ in having one or more ovaria, in the existence or absence of albumen, in the imbricate or valvular æstivation.
Any one of these characters singly is frequently of more than generic importance, though here even when all taken together they appear insufficient to separate Cnestis from Connarus."
To give an example amongst insects: in one great division of the Hymenoptera, the antennæ, as Westwood has remarked, are most constant in structure; in another division they differ much, and the differences are of quite subordinate value in classification; yet no one will say that the antennæ in these two divisions of the same order are of unequal physiological importance.
Any number of instances could be given of the varying importance for classification of the same important organ within the same group of beings.
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