;300 



SCIENCE. 



[Vol. X. No. 254 



•paper by Professor Trowbridge, read before the National Academy, 

 and noticed in Scienct- of Nov. i8, 18S7. Tliose who heard or have 

 read Professor Trowbridge's paper will remember that it reported 

 •the discover)' by his son of a peculiar structure in the primary 

 wing-feathers of soaring birds, by which they are locked when ex- 

 panded, and are thus maintained in position without muscular 

 effort. This structure is shown only in the primary feathers, and 



■ is therefore a character belonging to the last division of the arm. 



Professor Wyman, in the note referred to, describes " a peculiar 

 ■arrangement of the bones and ligaments in the wing of the pin- 

 tailed duck, by which, while the wing is fully extended, all the seg- 

 •ments of this extremity are fixed and retained in position independ- 

 ■-ently of muscular action." His account of the mechanism of the 

 -wing is as follows : — 



"The structure of the articulations of the elbow and wrist is 

 such, that during flexion and extension the radius advances and 

 recedes upon the ulna, carrying with it the upper carpal bone, and 

 this last the hand; in this way flexion and extension of the bones 



■ are effected. The lower carpal bone is attached to the upper by 

 strong ligaments : consequently, when the upper carpal bone is 

 drawn over the extremity of the ulna as the radius recedes, the lower 

 one is drawn up between the hand and the extremity of the ulna, 



■ and, acting as a wedge, maintains the hand extended, until it is dis- 

 placed by the reversed action of the radius." This structure, ac- 

 cordino- to Professor Wyman, shows how the extension of the bony 



■ framework of the wing may be maintained indefinitely without 

 fatigue. The structure of the primary wing-feathers described by 



JProfessor Trowbridge indicates that they too may be locked in 

 position, and thus the rigidity of the wing may be maintained auto- 

 matically to its extremity. 



None of the members of the National Academy who took part in 

 the discussion which followed the reading of Professor Trow- 

 bridge's paper seemed to have any knowledge of this discovery of 

 Professor Wyman ; and it was remarked, that, while the facts cited 

 ;by Professor Trowbridge seemed to explain the automatic exten- 

 -sion of the primaries which are appendages of the manns, the 

 rigidity of the arm itself, apparently manifested in the flight of soar- 

 ting birds, was yet unaccounted for. That missing link was sup- 

 plied by Professor Wyman, but, from his characteristic modesty, 

 rso quietly announced that it has been known to few. 



The case cited by me at the meeting of the National Academy 

 was a turkey-buzzard, shot when soaring over the prairies in the 

 Sacramento valley. Its wings remained rigidly extended, and it 

 descended slowly like a parachute and settled in the grass very 

 rnear me, quite dead ; even then the wings remaining expanded. 



Professor Storer gives other interesting examples. He says, 

 -" Upon the New England seaboard nothing is more familiar to old 

 gunners than the phenomenon that a bird shot in mid-air will often 

 ' set his wings ' and scale down toward the horizon, to reach the 

 water dead, often at a great distance from the boat whence the 

 ■shot was fired. Even in childhood I remembered to have won- 

 dered, when ' assisting ' at the shooting of duck and coot, as to the 

 ! meaning of the not infrequent exclamation, ' That fellow has set 

 ■his wings ; watch him ! ' " 



Dr. Storer writes that he was present at the meeting of the Bos- 

 ton Natural History Society, Sept. i, 1855, when Professor Wyman 

 ■exhibited his preparation of the duck's wing, and gave an explana- 

 tion of its structure which seemed a demonstration. 



Now, if some good anatomist would review the subject again, 

 ■ combine the results reached by Professor Wyman and Professor 

 Trowbridge, and illustrate his memoir with good figures, he would 

 make an important contribution to biological science. 



J. S. Newberry. 



New York, Dec. lo. 



The Origin of the Tritubercular Type of Mammalian 

 Dentition. 



Professor Cope has fully demonstrated that the molar teeth 

 of many divisions of the higher mammalia are derived from the 

 .tritubercular type of molar which is so abundant in the mammals 

 of the Puerco, or lowest eocene period. He has further (' Origin 

 of the Fittest,' p. 347) shown that the tritubercular type may be 

 traced back to the single cone of the reptilian crown by the follow- 



ing succession : ' first, a simple cone or reptilian crown alternating 

 with that of the other jaw; second, a cone with lateral denticles ; 

 third, the denticles to the inner side of the crown forming a three- 

 sided prism, with tritubercular apex, which alternates with that of 

 the opposite jaw,' etc. In the last meeting of the American Asso- 

 ciation for the Advancement of Science, Professor Cope applied this 

 succession to the origin of what he has called the ' tubercular-sec- 

 torial ' molar, citing the molars of Owen's genus Spalacotherium as 

 an instance of the transformation into the tritubercular crown in 

 process. I had independently arrived at the same conclusion, and, 

 moreover, found that the origin of the tritubercular crown in all its 

 various stages could be traced in the mesozoic mammalia. This 

 is traced in a memoir now publishing by the Philadelphia Acad- 

 emy. I am glad to be able to confirm Professor Cope's views in 

 every particular, for his numerous and suggestive papers upon the 

 mechanical genesis of tooth forms have placed comparative anato- 

 mists generally in his debt. Among the mesozoic mammalia the 

 simple large cone with small lateral denticles is seen in the Ameri- 

 can triassic genus Deomotherium. From the same beds Micro- 

 co7iodon furnishes a more advanced stage in the growth of the lat- 

 eral denticles into cusps. The mandibles of Jurassic genera 

 P hascolotherium, Menacodon, Spalacoiherium, furnish three 

 stages of the rotation inwards of the lateral cusps, accompanied 

 probably by the rotation outwards of the lateral cusps in the upper 

 jaw. In Stylodon this process is complete, the teeth being dis- 

 tinctly tritubercular, with the addition of a posterior heel, the upper 

 molars reversing the pattern of the lower. In another line of gen- 

 era the lateral cusps show no tendency to rotate inwards, but con- 

 tinually augment in size, such as Triconodon and its successors, 

 leading to the modern Thylacznus type of molar. In Amphzthe- 

 rziiin and many other genera it appears as if the posterior lateral 

 cusp had never been acquired, and the crown is re-enforced by the 

 inward extension of the cingulum, as seen in an early stage in 

 Diplocynodon. In Kurtodon, by the union of the external tuber- 

 cles in the upper jaw, we observe a columnar molar of the rodent 

 type. Itrnow appears as if we should soon be in possession of 

 sufficient data to trace the entire history of the multi-cuspid and 

 multi-fanged mammalian molar from the single reptilian cone and 

 fang. Henry F. Osborn. 



Princeton. N.J., Dec. 12. 



Iroquois and Eskimos. 



In connection with the dicussion which has recently appeared in 

 Science on the ancient relations of the Iroquois and Eskimos, a 

 passage which I recently came across in the manuscripts of the 

 Moravian missionary Christopher Pyrlseus is worthy of note. 



The active work of Pyrteus was between 1740 and 1750, and he 

 became an accomplished scholar in one or more of the Iroquois 

 dialects. In July, 1749, the Iroquois sent a deputation to a council 

 at Philadelphia, when Pyrteus acted as interpreter. In his notes 

 of his conversations with the deputies he has the following : — 



" Tschiechrohtie heissen die Gronlander ; . . . Tsckie, ein See- 

 hund. Die drei obgenannte Seneker wussten nicht nur von den 

 Gronlandern, sondern auch ihrer Contry {sic), Landsart, Kleidung, 

 Nahrung," etc. 



Of course, Pyrlseus used the term ' Greenlanders ' as generic for 

 ' Eskimos.' Evidently the Iroquois, who pushed their war parties 

 to the south as far as the present State of Louisiana, carried their 

 excursions also as far north as the shores of the Frozen Ocean. 



D. G. Brinton. 



Media, Penn., Dec. 7. 



The Sioux. 



In your issue of Nov. 25 (p. 264) your correspondent from Lex- 

 ington, Mo., says, " The Sioux call themselves Lah-ko-ta." In 

 this he is correct ; but when he adds, "not Dakota," he is in error. 

 The sounds of / and d are interchanged among certain Dakota dia- 

 lects. The Sioux who dwell east of the Missouri say Dakota, while 

 most of those on the west side (Tetons) say Lakota {vide Riggs's 

 Grammar and Dictionary of ike Dakota Language, p. 133). 



In giving the meaning of the name as ' cut-throats,' he is at vari- 

 ance with the best authorities on the Dakota language. 



W. Matthews. 



Washington, D.C., Nov. 26. 



