] 2 Mr. W. P. Pycraf t on the 



In Saxicola the 10th remex is longer than the covert of the 

 9th, but shorter than the remainder of the primary-coverts. 

 In Cussypha this remex is nearly as long as the -1th primary — 

 reckoning from the wrist — and markedly longer than the 

 remaining primary-coverts. The covert of the 10th remex, 

 by the way, is vestigial both in Cossypha and Saxicola. In 

 Cisticola the coverts of both the 9th and 10th remiges are 

 vestigial. In Turdus the 10th remex is longer than the series 

 of primary-coverts ; its covert is wanting, whilst the covert 

 of the 9th remex is extremely reduced. 



The carpal covert in Zeledonia, Cossypha, Saxicola, and 

 Erithacus is large, in Cisticola small. There is no carpal 

 remex in Zeledonia. 



The general form of the extended wing is rounded in 

 Zeledonia ; and therein it contrasts strongly with the wings 

 of Saxicola or Cossypha, for example. But this is a character 

 utterly valueless for systematic purposes. The shortening 

 and rounding of the wing apparently follows upon a lessened 

 use of this member or is brought about by adaptation to 

 flight in thick woods or undergrowth. 



The great range of variability which is to be met with even 

 among those members of the group which are admittedly 

 and undoubtedly closely allied, should be regarded as good 

 evidence in favour of this contention — that the form of the 

 wing is correlated with the habits of the bird, and is there- 

 fore of no value for systematic purposes. 



Grandala ccelicolor affords a good illustration of this. A 

 close ally of Zeledonia, an indubitable Thrush, yet its wing 

 recalls strongly that of the Swallows — or of Artamus, for 

 example. The primaries are pf great length, and the 9th is 

 the longest. The 10th is reduced to a vestigial condition, 

 and although, even when thus reduced, it is longer than the 

 covert of the 9th remex, it is several times shorter than 

 others of the primary-coverts. The covert of the 10th remex 

 has disappeared entirely. 



The peculiar shape of this wing suggests a habit of 

 flight resembling that of the forms with which it is 

 compared. 



