Page:The Zoologist, 4th series, vol 2 (1898).djvu/330

298 extinction), and their dominant character, as shown by their wide distribution and the prodigious number of similar species and individuals, must be thought to be the most recent. The following order correctly expresses the phylogeny as indicated above, whilst paying some regard to collateral relationship also, viz. *Caradrinina, *Notodontina, Lasiocampina, *Papilionina, Pyralidina, Psychina, *Tortricina, Tineina, Micropterygina; where the asterisk marks terminal developments.

It is not uncommon to see futile discussions as to which of two groups, reached by different lines of descent, is the higher, i.e. the more highly organized. The question is not only always unanswerable, but the answer would be quite valueless if found; all that can be done is to find the more recent.

In conclusion, a word as to the practical value of structural characters in classification. Characters of colour and general form are bad only because they are particularly liable to be modified by changes of environment. Now some structural characters are quite as liable, and are therefore equally bad. For example, in birds the shape of the beak is obviously likely to be modified in accordance with a change of food, and is therefore (as between allied forms) probably little better than a colour character. Yet the teeth of mammals, used for the same purpose, afford an excellent character, because the element of number comes in, which gives definition and admits of greater variation. It may be doubted whether any group of animals exhibits a better character than the neuration of insects, which displays sufficient complexity and variation in the number and interconnection of the different veins, whilst at the same time it is practically unaffected by external forces, except occasionally the easily calculable influence of a change in form of wing; moreover, the modifications effected are often irrevocable, and therefore less puzzling to follow.