J 6 



SCD 



[Vol. XIII. No. 309 



The action suggested would clearly be to some extent efficient . 

 Ijut would it also be sufficient? Can the gradients of velocity, etc 

 ■from level to level in air-currents far above us, be rapid enough t 

 :give the bird more than a slight assistance, although perhaps 1 

 would still avail himself of even that little help ? For here is mut, 

 more than " friction " to be overcome. If a hawk, weighing 

 pound or more to every square foot of effective wing and t,- 

 ■surface, would fall through the air with outspread motionle 

 wings ten miles an hour, which I believe to be a low estimate, thf 

 "to sustain his weight without muscular effort, his horizontal velof 

 relative to the surrounding air should be not less than fifteen rr, 

 -an hour. Can it be that air-currents hundreds of feet from 

 ■€arth, and only a few yards apart, often differ in velocity so m 

 -as that? And yet I have seen no other theory that could in 

 • least explain the prolonged soaring of birds, if, indeed, their wiui^ 

 do remain motionless. Much has been said of late, in " Science " ai 

 ■elsewhere, of the locking of certain wing-joints : but this admirab' 

 •contrivance for relieving muscular fatigue is quite irrelevant to,* 

 present problem ; for, as Mr. Gilbert has recognized, it prov 

 not a foot-pound of that actual work which, to prevent a fall t)f 

 miles per hour, must be expended at a rate of thirty mile-pounds 

 'hour if the bird weighs three pounds. 



A naval officer, whose name I forget, once told me of an obse 

 ■vation of his own, which, if confirmed, would remove all difficL 

 ties. Standing on deck in mid-ocean in a stiff breeze, he observe, 

 ■certain sea-birds hovering near him with apparently unmovin-^ 

 wings, though holding their own against the wind. But whe 

 they came within a few yards, he could see that the outsprea 

 wings had in reality a rapid motion of very small amplitude, almost 

 -a mere tremor. His impression was, that, though the wings had 

 not sufficient play to present the whole wing edgewise to the air 

 ■during the up-stroke, and flatwise during the down-stroke, yet the 

 •individual wing-feathers might be doing this, their vanes auto- 

 matically separating and turning edgewise, opening like valves or 

 like slats of a blind, as the wing rose, and closing up again, as it 

 fell, by the action of the air itself. Some such action of the feath- 

 ers would greatly aid this kind of flight. It is for naturalists to 

 say how well they are adapted to it, and whether such flight 

 might be possible- while the wing-joints remained locked, and 

 whether it might therefore be sometimes a restful change for the 

 4)ird. J. E. Oliver. 



Cornell University, Dec. 19. 



>le gradation between the rudimentary stage and the most 

 ■ developed condition seems to occur within the same group 

 questionably nearly related birds. 



Leonhard Stejneger. 



:»nian Institution, Washington, D.C., 



Cucullaris Propatagialis in Oscinine Birds. 



Some time ago ("Science," ix. 1887, pp. 623, 624), Dr. R. W. 

 -Shufeldt announced the alleged discovery in the bird-wing, of a 

 ■muscle well known as Cticullaris propatagialis, as being particu- 

 larly characteristic of the suborder Oscines (or, as I call them, the 

 superfamily Passo-oidea:), special stress being laid on itstaxonomic 

 -value in distinguishing the latter from the mesomyodian Passeres. 

 In a subsequent number of "Science" (x. 1887, pp. 70-72) I de- 

 monstrated that the muscle in question is particularly well devel- 

 •oped in parrots and woodpeckers ; and I also stated that I had 

 found it, though in a rudimentary state, in some of our typical 

 mesomyodian Passeres, notably in Tyrannus tyrannus. 



Through the courtesy of Mr. Frederic Lucas, I have since been 

 enabled to dissect a fresh specimen of the Nepal Hill-Myna 

 {Gracula intermedia'), a sturnine bird from India. I found the 

 Citciillaris propatagialis quite as rudimentary as in the Tyrannus 

 -alluded to. As Gracula undoubtedly belongs to the Oscines, it has 

 been fairly demonstrated that the muscle in question is neither 

 jpeculiar to the Oscines, nor especially characteristic of them. 



In looking further into the literature, I find, also, that Fiirbringer 

 has recorded the same muscle as being rudimentary in the follow- 

 ing oscinine birds, — Lainprotornis insidiator. Pastor roseus, 

 Myiagra cm'zdea, Ixos chrysorrhoeus, Copsychus macrurus, and 

 Tier dtis pilaris, — while in many others he found it but very feebly 

 developed. 



It is evident, therefore, that this variable muscular slip has no 

 taxonomic value whatever in the direction indicated by Dr. Shu- 

 feldt. I even doubt whether it will be found of much service in 

 ■defining trenchantly even families or smaller groups, since every 



Origin of Fish in Isolated Ponds. — If no one else will 



er Mr. C. B. Palmer's question, let me point out that nothing 



,^ s simpler than that birds, lighting on the edge of first one 



, then another, should carry on their feet the eggs, larvas, or 



atever it may be, of one to the other. In digging wells in a 



te desert region in Arizona, many miles from other wells, I was 



irst surprised to find them peopled after a short time with ani- 



■1 ds (frogs, if I forget not) which could not possibly have hopped 



;■ crawled from the nearest water, across the burning sand in mid- 



immer, with the thermometer rising above 115° F. But I soon 



aw the above easy explanation. HENRY M. Howe. 



Boston, Dec. 22. 



40. Felspar, or Feldspar? — The note on the spelling of 

 the word "feldspar," in " Science " of Dec. 14, is satisfactory with 

 the exception of its closing sentence, which says that the form 

 " felspar," although wrong, had been so long employed that "no 

 one who prefers it can be criticised for using it." It should be 

 added to this, that all other nations except Great Britain and her 

 colonies, and also that ninety-nine hundredths of all mineralogical 

 literature, spell the word with the d (or with the substitute / if the 

 language requires it), and they do so because this is etymologically 

 right ; that the English drop the letter because the error in Great 

 Britain has been persisted in until it has become English; and that 

 such national prejudice is not a legitimate ground for scientific ac- 

 tion even in Great Britain. Years since, the writer, thinking, like 

 many others, uniformity in scientific nomenclature very desirable, 

 sent a short paper, giving the British history of the word, to the 

 " London Philological Magazine," which was accepted, and pub- 

 lished anonymously as was requested. But national prejudice 

 proved to be superior to all other considerations. In this country 

 the prejudice has no right to a place, and the transplanting of its 

 effects should not be allowed without a protest. J. D. D. 



41. The " Supernumerary Molar " in Man. — As a partial 

 reply to Query 41 in " Science " of Dec. 7, permit me to state that Dr. 

 Shufeldt will find in skull No. 1327, of the Morton collection in the 

 Philadelphia Academy of Natural Sciences, the finest specimen ex- 

 tant of molars posterior to the third or " wisdom " teeth. It is some 

 years since we saw it, and then " as through a glass " only ; but 

 our recollection of it is that the superior fourth molars are quite 

 through the alveolar process, while the inferior are just seen from 

 above in their course to the surface. The superior fourth molars 

 are not " peg-like," but molar-like, though smaller than their 

 neighbors. The specimen is^ Australian. We have a personal 

 acquaintance who has eighteen teeth in the upper jaw ; the " extra " 

 teeth, one on each side, posterior to the third molar or " wisdom " 

 teeth. Like Dr. Shufeldt's specimen, these are " conical, peg-like," 

 as to form of crown. According to dental writers, the African races 

 seem specially favored in this matter. For the best account of this 

 structure in man (assuming it to be " supernumerary "), reference 

 is made to the late Dr. M. S. Dean's translation of Magitot and Se- 

 gros' " Dental Follicle," in which it is made to appear that the set- 

 ting of an epithelial structure, and the enamel organ, determine 

 the fact and position of the future tooth. The same process is 

 made to account for " supernumerary " teeth elsewhere in the 

 maxillae, the anterior part of the upper being particularly favored. 

 As to its significance, facts are accumulating that seem to point to 

 the weeding-out of the third molar or " wisdom " tooth, the num- 

 ber and importance of the facts being directly as civilization. Such 

 being the case, is it unreasonable to suppose thisoccasionally-crop- 

 ping-out fourth molar other than a reversion to a past type, and to 

 a time in the history of man when mastication was the primary, 

 and not as now, in the. civilized world at least, a secondary func- 

 tion ? L. E. J. 



