" quintocubitalism: " in the wiisra of bieds. 235 



of incipient quills might arise in the position required for the 

 diastataxic gap. Among Aves there is a general correspondence 

 with the conditions among Columbse. The diastataxic condition 

 of the wing is primitive among birds ; it is the architaxic 

 condition. By closing up of the ranks any architaxic wing may 

 become eutaxic, and this change has been made by some whole 

 groups and by individuals of other groups. 



Bibliography. 



(1) Weat. — " On some Points in the Morphology of the Wing 



of Birds." P. Z. S. 1887, p. 343. 



(2) Beddaed. — Structure and Classification of Birds. London, 



1898. 



(3) GrAEEOD. — " On some Points in the Anatomy of the Qo- 



Imnhce:' P. Z. S. 1874, p. 249. 



(4) PtJEBETiirGEE. — TJutersuchungen zur Morphologic und 



Systematik der Vogel (1888). 



(5) Chalmees Mitchell.—" On the Perforated Plexor Muscles 



in some Birds." P. Z. S. 1894, p. 495. 



(6) Chalmees Mitchell. — " A Contribution to the Anatomy of 



the Hoatziu." P. Z. S. 1896, p. 618. 



(7) Chalmees Mitchell. — " On the Intestinal Tract of Birds." 



P. Z. S. 1896, p. 136. 



(8) Beddaed & Paesoists. — " On certain Points in the Anatomy 



of the Parrots." P. Z. S. 1893, p. 507. 



(9) PrcEAET. — " A Contribution towards our Knowledge of the 



Morphology of the Owls." Trans. Linn. Soc, Zool. vol. vii. 

 (1898) p. 223, pis. xxiv.-xxix. 



EXPLANATION OF THE PLATES. 



Plate 12. 



Fig. 1. Geopelia cuneata, left wing : showing primaries and coverts, carpal 



remex and covert, and even series of secondaries and coverts ; no gap, 



Eutaxic condition. 

 Fig. 2. Leucosarcia picata, left wing : showing primaries and coverts, carpal 



remex and covert, and even secondary series without gap. Eutaxic 



condition. 

 Fig. 3. Geophaps plumifera, left wing : showing the primaries and coverts, the 



carpal remex and covert, the secondaries and coverts without a gap, 



Eutaxic condition. 



