NOVEMBEB 12, 1915] 



SCIENCE 



685 



trolytes (Walker and Kendall). The results in 

 all cases confirm the assumption that the correc- 

 tion thus applied is valid and complete. 



Extremes of Adaptation in CarnivoroiiS Dinosaurs, 

 Tyrannosaurs and Ornithominius : Henry Fair- 

 field OSBOKN. 



Complete skeletons of two of the most remark- 

 able types of carnivorous dinosaurs, Tyranno- 

 saurus and Ornithominius, are mounted and ex- 

 hibited especially at this meeting of the academy. 

 Dr. Osborn will describe the two extremes of car- 

 nivorous dinosaur adaptation which they respec- 

 tively represent. 



Influence of Certain Minerals on the Development 

 of Schists and Gneisses: C. K. Leith. (Intro- 

 duced by 0. R. Van Hise.) 

 A brief account of the development of quantita- 

 tive methods in the study of the metamorphic 

 cycle, leading up to a consideration of the forma- 

 tion of schists and gneisses. Evidence is pre- 

 sented to show that the development of schists and 

 gneisses means convergence to a few mineral types, 

 and that the characteristics of a few minerals de- 

 termine to a large extent the course of chemical, 

 mineralogieal and textural changes in dynamic 

 metamorphism. 



Sculpture of the Mission Mange, Montana: W. M. 



Davis. 



The Mission Eange, one of the smaller members 

 of the Eoeky Mountains in western Montana, com- 

 posed of deformed rocks, chiefly quartzites, has the 

 appearance of a tilted and dissected fault block, 

 trending north and south, about 70 miles in length. 

 The steeper face, probably representing the bat- 

 tered fault scarp, looks to the west. The low 

 northern crest of the range emerges from the gla- 

 cial deposits that floor the surrounding intermout 

 depression at an altitude of 3,000 feet, and rises 

 slowly southward with moderate undulation to an 

 altitude of 9,500 feet near its abrupt southern 

 end. The eastern side of the range is said to slope 

 more gently than the steep western face. The 

 present features of the range due to erosion since 

 uplift, as seen from the interment depression on 

 the west, may be divided into three oblique belts 

 by two nearly parallel south-dipping planes, 

 about 1,000 feet apart. The middle belt has 

 smoothly-rounded summits, and full-bodied, large- 

 textured, waste-covered spurs of mature normal 

 degradation between wide-spaced, steep-pitching, 

 consequent valleys. The upper and southernmost 

 belt includes, besides the rounded, waste-covered 

 forms of normal erosion, bare-walled cirques and 



troughs of local glaciation in more than a score of 

 its high -reaching valleys; these features are best 

 developed at the high southern end of the range, 

 where the crest is locally sharpened into Alpine 

 aretes, and where the troughs, encroaching most 

 broadly on the intervening spurs, reach down to the 

 mountain base; at the middle of the range where 

 its height is less, the cirques are faintly developed 

 and the troughs extend only a few hundred feet 

 down these valleys. The lower and northernmost 

 belt shows many crags and knobs, elifCs and 

 ledges, channels and hollows due to erosion by a 

 broad and overwhelming glacier of Canadian 

 origin. The northern half of this belt, or roughly, 

 the northernmost fourth of the range, lies entirely 

 beneath the slanting limit of Canadian glacial ac- 

 tion, and is of disorderly form to its crest; the 

 northernmost knobs, more or less detached from 

 one another, rise hardly a hundred feet above the 

 gravel plain: the southern half of the belt, in the 

 second fourth of the range, preserves rounded nor- 

 mal forms along its crest and lower and lower 

 down on its flanks as mid-range-length is ap- 

 proached ; its valleys are barred across by morainie 

 embankments along the slanting limit of the 

 Canadian glacial action, and its spurs are imper- 

 fectly truncated in rugged facets which descend 

 abruptly into Flathead lake. The height of the 

 facets and the altitude of the embankments de- 

 crease southward; the facets become smaller and 

 less continuous; the embankments become longer, 

 larger and more continuous, until, curving away 

 from the range base they unite in a noble terminal 

 moraine, 400 or 500 feet in height and a mile or 

 more in breadth, which swings westward across 

 the intermont depression, separating Flathead lake 

 on its northern concave side from the Mission 

 plains of earlier glaciation on its southern, con- 

 vex side. As far as I have seen and read, the 

 Mission range is unique in its systematic tripartite 

 arrangement of normal and glacial features. 



Crystallization of Quartz Veins: Waldemae Lind- 



GEEN. 



The Minor Constituents of Meteorites: George P. 



Merrill. (Introduced by A. L. Day.) 

 A Peculiar Clay from near the City of Mexico: E. 



W. HiLGARD. 



KAML EUGEN GVTEE 



At the first meeting of the year the presi- 

 dent of the Research Club of the University of 

 Michigan read the following words of appre- 

 ciation of the late Professor Guthe: 



