ME. E. DEGEX 01^ ECDTSIS. 409 



they were stripped off one after the other as in the case of the " Remicle " and other 

 diminutive terminal coverts. A likely procedure for feathers which at no time could 

 have been of any considerable size, and certainly not more in number than three at 

 the most. 



The moult of the "Pennse pollicis," moreover, synchronizing with that of Metacarpo- 

 digitals VI.-X. and Cubitals I. -IV. (see Table VI.), is by no means an unimportant 

 item for the argument that in their retrograde movement they were obstructed by the 

 position which these latter, together with the " intercalaries " (as representing the 

 metacarpal equivalents for Digit II.), had early taken up on the distal portion of 

 the cubitus. 



Finally, if the present inquiry into the moult of the individual bird, which, however, 

 reflects all the phylogenetic conditions inherent to the Class as a whole (except perhaps 

 the Spheniscidae), has not thrown any further light upon the question as to whether 

 " diastataxy " is due to either the hypothetical absence of a remex or the assumed 

 presence, consequent upon the " shifting" process alone, as summarized by Pycraft (in 

 his paragraph (1) p. 241, I. c), it should at least have contributed materially towards 

 the outstanding answer of the first part of the latter author's paragraph (3) — " The 

 cause of this shifting is still a matter for investigation " ; and also to the second part 

 of the same sentence — " it is possibly due to a slight secondary lengthening of the 

 forearm." 



This latter interpretation does not seem to gather strength, especially when we 

 perceive the ample manner in which the " moult " supplies the proof that " faulting " is 

 not confined alone to diastataxic wings, but takes place, though in inferior degree, in 

 the short-armed eutaxic forms of birds, such as the Passeres. 



My sincere thanks are due to the following gentlemen : — 



To Mr. J. Orme, of the Victorian Railways, Murchison East, Victoria, Australia, 

 who by his disinterestedness in supplying me with the specimens has so materially 

 aided me in my task. 



To Dr. R. Bowdler Sharpe, of the British Museum (Nat. Hist.), for his interest 

 shown in its progress and encouraging me in its completion. 



To Dr. Chalmers Mitchell, F.Z.S., F.L.S., &c., for his valuable advice and sugges- 

 tions made on the form of this memoir and its preparation for publication. 



To C. Davies Sherborn, Esq., F.Z.S., for his generous act of revising the MS. 



To the Editor, for the facilities given me in kindly placing at my disposal the use 

 of the Library of the Zoological Society. 



Also to the Staff of the Society's Library and the Publication Department, for the 

 ever-courteous manner in which my wants were met. 



