°i897 J DwiGHT, The PkiladelpJiia Vireo. 2*1 \ 



There are a few pin-point new feathers on the breast, the crown 

 and the back ; the ninth and eighth primaries have been replaced 

 by new quills one quarter grown, the ninth slightly longer than 

 the eighth, and the seventh barely shows as a minute follicle. 

 Specimens taken later show the progress of the moult which is 

 complete, body-feathers, wings and tail. There is considerable 

 individual variation in the sequence of development of the feathers 

 of the different tracts, but the development is pretty uniform on 

 the whole and seems to radiate from various centres. The earliest 

 new feathers appear on the breast, near the forking of the inferior 

 feather-tract, and on the back in the interscapular region. The 

 crown shortly begins to moult and the inner primary (the ninth 

 by count) falls quickly followed by the eighth. The body 

 plumage is quite rapidly renewed, the corresponding primaries of 

 each wing slowly falling in pairs with their coverts so that the body 

 plumage is largely renewed before the outer primaries fall. The 

 wing-coverts begin to be renewed after the primaries begin to fall 

 and are usually complete before the outer primaries are replaced. 

 The outer members of the rows are the first "to be moulted and 

 this also applies to the tertiaries which are completely renewed 

 before the secondaries begin to fall. This occurs when only 

 three or four of the old outer primaries remain, and the rectrices 

 also fall at this stage, or a little before, beginning with the middle 

 pair. The outer secondary of each wing falls first while the inner 

 secondary and the alula are the last parts of the wing to be 

 renewed. The renewal of the body plumage is usually very 

 well under way before the moult is conspicuous in the wings, but 

 the last traces of new growth are usually a few auricular and 

 abdominal feathers and perhaps a few on the chin and scapular 

 region. A bird of August 4 is particularly instructive. All that 

 remains of the old dress are a few auricular, scapular and abdom- 

 inal feathers of the body plumage, the outer pair of rectrices of the 

 tail, the three outer primaries, their coverts, the alula, the five 

 inner secondaries, and much of the lining of the winf^. 



I have followed the moult with considerable detail because noth- 

 ing has been known regarding it in this particular species, 

 and it seems probable from the material I have handled that it is 

 typical of all of our Vireos. 



