23G MB. W. p. PTCEAFT ON SO-CALLED 



Plate 13. 



l*'ig. 4. Columbula jpicm, left wing ; carpal covert and remex ; series of coverts 



and secondaries : showing the eutaxic condition. 

 Fig. 5. Geotri/gon montana, left wing ; 1st primary ; carpal remex and covert ; 



series of secondaries and coverts : showing reduced diastataxic condition. 

 Fig. 6. Starncenas cycmocephcda, left wing ; carpal remex and covert ; six 



secondaries and coverts in even series. Eutaxic arrangement. 

 Fig. 7. Turtur chinensis, left wing ; carpal covert and remex; four secondaries 



and coverts ; diastataxic gap with covert ; two secondaries with 



coverts. 



Some Facts concerning the so-called " Aquintocubitalism " ia 

 tlie Bird's Wing. By W. P. PrcKAFT, A.L.S.* 



[Eead 16th March, 1899.] 



(Plates 14-16.) 



Contents. 



Page 



Introductory Remarks 236 



Eutaxic and Diastataxic Wings 237 



The Embryo Wing 238 



Summary of the foregoing Remarks 241 



Evidence in support of the above Conclusions 241 



A possible Objection 244 



The Carpal Covert and Remex 24.5 



Explanations of Diastataxy 246 



Exceptions 247 



Facts correlated with Diastataxy 249 



Some Degenerate Wings 250 



The Probable Origin of the Diastataxic Wing 252 



Diastataxy as a Factor in Classification 264 



Introductory SemarTcs. 



The feathers in the typical bird's wing, e. g., the Common 

 Fowl, are divisible into two groups — tectrices or coverts, and 

 remiges or flight-feathers, commonly known as " quills." 



The remiges form a single row of feathers running aloug the 

 post-axial border of the wing from the tip of the index-digit 

 inwards to the elbow-joint. Those of the hand constitute the 

 primaries, those of the forearm the secondaries. With the 

 primaries we have little or nothing to do in this connection ; 

 suffice it to say that they never, in the Carinatse, exceed 12 in 

 * Cf. Editorial footnote on p. 21 



