xxu 



the whole series of remiges, which ought to be there, is 

 absent. The series of feathers on the '' parapteron " is 

 developed under exactly the same conditions as both the 

 '' primary ■" and '" secondary " series of remiges, excepting 

 that in the parapteron the remiges are entirely wanting. 

 This possibility of suppression of flight-feathers, while the 

 coverts 'are retained, affords an explanation of the case of 

 the 5th cubital remex and the correlation of the covert- 

 feather on the wrist. 



These notes have been put together at the request of my 

 friend Dr. Sharpe on the eve of my departure to my new 

 home in Australia, where I hope to find opportunity and 

 time to further pursue my studies by following up the 

 analogy on to the scapular tract, where I believe I have 

 found similar traces of remigial suppression. I would pro- 

 pose the term " pterylomorphism " for the phenomenon of 

 suppressed quills with the retention of their main coverts. 



We must go back to a very remote parent stock for a full 

 comprehension of the phenomenon, for the deduction follows 

 from the fact that, save the primitive or vestigial remex on 

 the wrist-joint, there are absolutely no positive traces of 

 other vestigial flight-feathers where they are absent at the 

 present day. The agency of their disappearance must 

 therefore be a very deep-rooted one. 



I will conclude with a fcAv remarks on the origin of aquinto- 

 cubitalism. To provide a plausible theory and explanation 

 of this extraordinary, if not mysterious, phenomenon in some 

 of the groups and families of Birds, it is necessary to revert 

 once more to our carpal covert, so incousequently placed, to 

 all appearances, in the bird^s wing, I believe it to be the 

 key to the entire problem of the evolution and morphology 

 of the fore limb of the bird. 



As I have already mentioned in my introductory remarks 

 to this paper, this feather is, apart from its colour in certain 

 cases, readily distinguishable from the rest of the major 

 coverts by its relative shortness, varying in degree, but never 

 attaiuiuij the length of the rest of the series. 



