486 THE NUMBER OF PRIMARIES IN OSCINES 



my inspection by Mr. J. A. Allen, the spurious primary is con- 

 spicuously displayed, exposed for a. third of an inch.* 



* Believing this to be an important matter deserving of farther investiga- 

 tion, I was not long since led to examine the general qnestion, with satisfac- 

 tory results. I verified Professor Baird's observations in many more cases, 

 extending them to include all our North American families excepting per- 

 haps Laniidw (in Lanius) and Ampelidce (in Ampelis). The clue to the 

 search for the apparently wanting primary was given by Baird (Review, pp. 

 160, 325), from which it appears that in all those Vireos which seem to have 

 only nine primaries, two little feathers, distinct in size and ehape and some- 

 what so in position, are found at the buse of the supposed first primary ; 

 while in Vireos, with obviously ten primaries, there is only one such little 

 feather. With the possible exception of Ampelis and Lanius, in which I 

 did not make out the state of the parts satisfactorily, I find that in all of 

 the numerous North American genera examined, those of ten primaries show 

 but one of these little feathers, while the rest have two. In the family A lau- 

 didw, as in Vireonidcs, some genera have ten primaries, others apparently 

 only nine ; and in our genus EremopMla, in which only nine are developed, 

 there are two of the little feathers just mentioned, the overlying one being 

 exactly like one of the primary coverts, the other, though not very similar, 

 more resembling an abortive primary. Alauda arvensis, which shows a 

 minute but obvious spurious quill, has but one such little feather; and in 

 Galerita cristata, with a spurious quill about two-thirds of an inch long, there 

 is likewise but one. In Clamatorial Passeres, perhaps without exception, 

 there are ten fully developed primaries, the first of which may equal or 

 exceed the next in length ; and in the single North American Clamatorial 

 family, Tyrannidce, I find, as before, only one of these little featners. In a 

 Woodpecker, remarkable among Pioarian birds for possessing only nine long 

 primaries, the first being short or spurious, there is also but one. 



It thns seems to be established that among supposed nine-primaried birds, 

 the additional one, making ten in all, is normally represented by the second 

 one of these tiny quills which overlie the base of the outermost f uUy devel- 

 oped feather ; it being this same little quill which in ten-primaried Oscines, 

 iu Clamaiores, and probably other birds, comes to the front and constitutes 

 the first regular primary, either remaining quite short, when it is the so-called 

 "spurious" primary, or lengthening to equal or exceed the other primaries 

 in extent. 



It becomes an interesting question whether both of these minute quills be 

 not rudimentary primaries, as one of them certainly is. I have failed to 

 detect any material difference between the two in size, shape, or position. 

 One overlies the other, indeed, as a covert should a primary, but the two are 

 together inserted side by side on the upper side of the first fully developed 

 quill ; both are rigid and acuminate, more like primaries than like coverts, 

 and both are abruptly shorter than the true primary coverts. So far, all 

 the evidence favors the supposition that both are rudiment ary primaries. 

 On the other hand, coloration is against such hypothesis, as in the original 

 case of Vireo flavifrons, in which Baird determined the underlying one of 

 these two little feathers to be the missing primary, mainly because it was 

 colored like the primaries, the overlying one resembling the coverts in colora- 



