ON SOME OF THE MAIN FEATURES IN THE 

 EVOLUTION OF THE BIRD^S WING. 



EDWARD D E G E N. 



(With Notes by W. P. Pycraft, M.B.O.U., Assistant to the 

 Liuacre Professor of Comparative Auatomy, Oxford.) 



The close attention which has been paid during recent years 

 to the study of the Pterylography of Birds shows that con- 

 siderable importance is attached to the character and arrange- 

 ment of the plumage as a factor in the classification, of the 

 Class Aves. Instead of regarding the feathering of the bird's 

 body as a mass of plumes arranged haphazard and without 

 significance^ it has been found by gradual study and exami- 

 nation that a perfect order and sequence of arrangement is 

 discernible^ and ornithologists have not disdained to employ 

 the distribution of the feather-tractS;, the presence or absence 

 of powder-down patches, the arrangement of the coverts and 

 the quills, &c,^ as aids to arriving at a natural classification 

 of Birds. 



The full recognition of the importance of Pterylography as 

 a means towards classification commenced with the work of 

 the great Nitzsch. It must be -remembered^ however^ that 

 Nitzsch chiefly directed his attention to the distribution of 

 the feather-tracts^ and did not treat of the relation of the 

 quills and the wing-coverts in any great detail. This subject 

 was elaborated by Sundevall; and in more recent days the 

 wings of birds have formed the objects of study of many 

 Avell-known anatomists. A new interest, however, was 

 imparted to the subject when the late Mr. R. S. Wray 



