108 Mr. Vigors's Repli/ to some Observations 



tlie family, and indicate a variation in that food as it gradually 

 descends from tlie hardest to the softest vegetahle substances. 



In addition to these characters others iiave been talicn into con- 

 sideration, which appeared to us of no mean vahie ; such as the 

 form of the wing and tail, and the relative proporlions of the 

 feathers of each ; the greater or less elevation of the tarsi; and 

 the structure of the tongue. These appear to be characters 

 which are not only prominent and easily recognized, and at the 

 same time indicative of various modifications in the economy of 

 the birds in which they are found ; but characters which have 

 already been employed as of the highest im))ortance by those 

 naturalists who have established leading groups in our science. 



The characters, for instance, taken from the structure and 

 proportions of the wing and tail must be considered of primary 

 consequence, as more or less conducive to the powers of flight : — 

 jSbwers, which it may be recollected form one of the typical dis- 

 tinctions between Birds and the other f-^ertebrata. It conse- 

 quently becomes a leading object of the naluralist to point out 

 the perfection or deficiency of these organs of flight by the most 

 marked distinctions in his power. In the present family he finds 

 an occasion of peculiar interest for the exercise of this privilege. 

 We may remember that the group of the Ferching Order, which 

 approaches most closely to the Rasorial, is the Tribe of Scamorcs. 

 One of the characteristicks by which this approach is indicated 

 is the decreasing powers of the wing in the Scansorial Birds. 

 And the naturalist, in marking the modifications by which these 

 latter birds gradually pass into the 7?«.90/vrt/ families, whose typical 

 station is on the ground, and who consequently require no superiour 

 powers of flight, is enabled to point out more strongly one of those 

 beautiful aflinities by which n;iture connects her leading forms. 



The greater or less elevation of the tarsus of a bird is again a 

 cluracter of much consequence, as indicating its habits to be 

 more or less terrestrial. And accordingly we find many important 

 groups, such as Mijiothe,"a, 111., and Pitta, Vieill., among the 

 Thrushes ; and Saxicola, Bechst., and Brachjjpteri/x, Horsf,, among 

 the Warblers ; with several others of acknowledged importance, 

 established chiefly upon the modifications of this character, ilcrc 



