I^O Correspondence. [April 



Classification of the Macrochires. 



To the Editors of the Auk : — 



Dear Sirs: — Dr. Shufeldt's letter in the October 'Auk,' last year, requires 

 only a few lines in reply from rav side. 



I am sorry that Dr. Shufeldt in "carefully reading a number of times" 

 the sentence commencing: "internally they differ," etc., failed to see that 

 the whole was a case of typographical error, and still more sorry that he 

 did not know "the kind of comparison he [I] wishes to institute between 

 the sternum of a Swift and a Swallow," when I referred to the bifurcate 

 manubrium and deeply "two-notched" sternum of the latter. Dr. Shufeldt 

 will probably believe me, when I state, that in the original, from which 

 the sentence in question was quoted, the kind of comparison was made 

 clear, and that the words "pointed manubrial process and no posterior 

 notches to the' — an entire line — has fallen out between "«" and "sternum." 

 I cannot prevent Dr. Shufeldt from taking exception to the remark that 

 the sternum is 'two-notched' in the Swallows, notwithstanding the fact 

 that he admits its having "a fair of notches in its xiphoidal extremity," 

 and my own belief that "a pair of notches" and "two notches" mean ex- 

 actly the same thing, but I must protest against his remark that "the two- 

 notched sternum is seen in such forms as Picus." To the uninitiated mind 

 it would seem to be a decided misnomer to call the sternum of Picus two- 

 notched when the fact remains, that it possesses four notches. "Such 

 forms as Picas" of course, have two notches on eacli side of the mesial line, 

 but Dr. Shufeldt will probably pardon me for not calling a horse a two- 

 legged animal, or a man a one-legged animal, notwithstanding the fact 

 that the v have respectively two legs and one leg on each side of the mesial 

 line. But if Dr. Shufeldt calls a horse a four-legged animal, why object to 

 calling the sternum of the Woodpeckers four-notched? 



In regard to the similarity or dissimilarity of the flight of the Swifts as 

 compared with that of the Swallows or Hummingbirds, I shall only re- 

 mark that Dr. Shufeldt's supposition that I would never have asked, "what 

 differences are there in the Swifts' flight from that of the Swallows' that 

 should have caused such a remarkable modification towards the Humming- 

 birds," if I "had ever had the opportunity to compare in nature the flight 

 of two such birds, for example, as Micropus melanoleucus and Tachycineta 

 thalassina" will not hold for the simple reason that I have had the oppor- 

 tunity to compare in nature the flights of several species of Swifts and 

 Swallows. I am also familiar with the flight of the Hummingbird, and in 

 spite of this, or rather just on account of my observations, do I reiterate 

 that the flight of the Swift is decidedly more like that of the Swallow than 

 it is like that of the Hummingbird. And I also insist that I am still with- 

 out an answer to the question, What in the nature of these birds' flight 

 has brought about such an extraordinary similarity, osteologically, myo- 

 logically. and pterylographically in the wing-structure of the Swifts and 

 Hummingbirds, as compared with that of the Swallows? For surely, it 

 cannot be denied, that the flying apparatus of Swifts and Hummers pos- 



