OCR Text |
Show 656 DR. H. GADOW ON THE REMIGES OF BIRDS. [Dec 18, especially in the Order of Passeres. The statements hitherto published are, however, not always in harmony with each other, and moreover are not free from mistakes. Considering that the results yielded by a renewed and more comprehensive examination of the points in question may possibly influence the systematic position of some genera or even subfamilies, I submit the following tables (pp. 658-664) for the acceptance of the Zoological Society of London. They contain the results of some investigations which I have recently made. Many of the specimens examined were fresh or had been preserved in spirits. Of many species several specimens have been examined, in order to exclude doubt, which occasionally arises, in the cases of moulting or imperfect or very small birds. The remarks which I have to offer are scanty, not only because the whole matter is rather dry, but because I have abstained from testing the taxonomic value of the arrangement of the terminal primaries by correlating their features with other known characters. At any rate the following tables show such considerable variations of the terminal quills within the limits of avowedly closely allied genera and subfamilies, that we ought to refrain from generalizations. The same remark applies to the presence or absence of the fifth cubital quill. Although this character was discovered by Gerbe in 1877, and has lately been rediscovered by "Wray, it remains still unexplained, young birds not throwing any light upon the question. The presence of this fifth quill is indicated by a + , its absence by a - in the accompanying tables. The other columns contain the total number of primaries, and the way in which this number is composed of metacarpal and the various digital quills. The most important result is evidence of the gradual reduction in number of the functional quills. With the exception of Struthio and the Spheniscidse, the number of primaries or metacarpo-digital quills varies between 12 and 10. Amongst the birds which possess 12 primaries, the Podicipedidse, many Pelargi, and Rhea possess 7 metacarpal and 5 digital quills, whilst Apteryx has 8 metacarpal and only 4 digital quills. In all other birds the reduction from 12 to 11 is due to the reduction from 7 to 6 of the metacarpal quills. Abdimia stands alone with 7 metacarpals, and only one quill carried by the second phalanx of the second digit. The 11th or terminal quill is never fully developed and hardly functional ; it is invariably much shortened, and. is hidden between its upper and lower covert ; not COUES, E. " On the Number of the Primaries in Oscines." Bull. Nuttall Ornith. Club, i. (1876), pp. 60-63. GERBE, Z. " Sur les plumes du TOI et leur mue." Bull. Soc. Zool. France, ii. (1877). pp. 289-290. JEI-FIUKS, J. A. "On the Number of Primaries in Birds." Bull. Nuttall Ornith. Club, vi. (1881), pp. 6-11. W R A Y , R. S. " On some Points in the Morphology of the Wings of Birds." Proc. Zool. Soc. 1887, pp. 343-357. FUERBRIXNGER, M. Untersuchungen zur Morphologie und Systematik der Vogel. Amsterdam, 4°, 1888. BAIRD. Review of North-American Birds. |