Page:The Zoologist, 4th series, vol 4 (1900).djvu/278

250 the Black-backed Crow-Shrike, or Piping Crow (Gymnorhina tibicen), erroneously, but very persistently, called Magpie by the colonists, collected during my stay in Australia, I decided, after reading with interest Dr. Butler's remarks on the subject, to seize the opportunity for trying to ascertain from such ample material the extent to which this principle might affect this particular species.

Dr. Butler's method for measuring the dried and mounted wing consists in ascertaining its length from the upper head of the upper arm-bone to the extreme tip of the longest of the flight-feathers, which is situated on the hand portion. Since any difference in the measurements can therefore only be the result of this longest of the primaries itself, I came to the inevitable conclusion that in this way no information at all is procurable in regard to the extent to which the rest of the remiges participate on the area of wing for supposed sexual difference, an adjunct of no mean importance in this question. To supply this deficiency necessitated the measuring of all the flight-feathers separately, on one side at least, which in the present case was that of the left-hand wing. This process was rendered somewhat easier from the fact that only three of the specimens examined were dry skins, all the others being preserved in spirit. There are ten primaries and also ten secondaries in the wing of this species. By commencing to count the primaries from the tip of the wing inwards, as Dr. Butler has done, the fourth flight-feather is found to be the longest of all. This makes this remex identical with the corresponding one of the song-birds proper, or Oscines, in which group it has been considered to be the third, owing to the "assumed" absence of the first or outermost remex. For this reason I have here followed the practice now generally adopted by systematists of counting the primaries from within—that is, the carpal joint, outwards to the extreme end. By doing this it will be found that the longest primary in this species is the seventh in number, same as in the case of the song-birds, where there is supposed to be one less, namely, the tenth.

All my measurements are expressed in millimetres. The highest figures for the seventh, or the longest primary, obtained for the twenty-seven specimens examined, are the following:—