968 



SCIENCE 



[N. S. Vol. XXV. No. 6S1 



tions, to give precise methods for determining the 

 position of the strain ellipsoid or the equipoten- 

 tiala in a slate, to show why there is no cleavage 

 on planes of maximum slide, and to explain 

 thermodynamically how it happens that the planes 

 on which the entire energy of deformation is ex- 

 pended are not those on which feldspar is con- 

 verted into mica. We are past the stage in which 

 mere opinions or general impressions should be 

 allowed decisive weight. 



At the conclusion of Mr. Becker's paper its 

 discussion was taken up by Mr. Bailey "Willis 

 with special reference to other theories of rock 

 cleavage. Mr. Willis called attention to the 

 very broad observational basis of the explana- 

 tions of rock cleavage given by Messrs. Van 

 Hise and Leith and pointed out that Mr. 

 Becker approached the problem as one of pure 

 mathematics and solved all the complex phe- 

 nomena by a single theoretical application of 

 principles. Granting the correctness of the 

 principles and their appropriate application 

 to a purely mechanical distortion, one may 

 very reasonably question their adequacy to 

 explain the facts emphasized by Leith, namely, 

 the rearrangement and recrystallization of 

 minerals with parallel orientation of crystal- 

 line cleavage and major axes of particles. 



Leith recognizes a variety of cleavage (frac- 

 ture-cleavage) developed in the planes of maxi- 

 mum slide, as Becker calls them, but limits 

 that development to the zone of fracture. 

 WiUis took exception to this limitation and 

 expressed the view that in regions of great 

 tangential movement displacement on planes 

 of maximum slide (i. e., on planes oblique to 

 the direction of tangential pressure) may oc- 

 cur in a deep-seated zone, where fracture is 

 impossible and flow cleavage develops by re- 

 crystallization and orientation in those oblique 

 planea. The Appalachian region of North 

 Carolina appears to present such displacement 

 with appropriate cleavage. 



On the other hand, there are regions where 

 the movements of large masses are essentially 

 vertical, as is shown by warping of the surface. 

 Such an area is that of the Canadian High- 

 lands. In so far as the vertical swelling may 

 be attributable to tangential stress it indicates 

 vertical elongation of the mass, which may be 



and probably is accompanied by recrystalliza- 

 tion and orientation of mineral particles, pro- 

 ducing flow cleavage in the normal planes. 



Thus it seems probable that cleavage in- 

 volves molecular rearrangement, of which 

 Becker does not take sufficient account, and 

 that flow cleavage may develop in oblique 

 planes, which Leith does not consider, as well 

 as in the normal planes, which he does recog- 

 nize. K. L. Faris, 



Secretary 



THE ANTHROPOLOGICAL SOCIETY OF ■WASHINGTON 



The annual meeting of the Washington 

 Anthropological Society was held May 28, 

 1907, with Mr. J. D. McGuire in the chair. 

 The program consisted of the annual report 

 of the treasurer; preliminary communica- 

 tions; notices of deceased members; and an- 

 nual election of officers. 



The treasurer's report showed that during 

 the fiscal year ending December 31, 1906, the 

 total receipts amounted to $587.Y8, the total 

 expenditures to $398.22, leaving a balance of 

 $189.56. 



Mr. Hewitt presented an extract of the 

 monthly field report of Dr. J. E. Swanton, 

 bearing on the scattered remnants of the In- 

 dian tribes in Louisiana. 



The obituary notices were delivered as fol- 

 lows : (1) Dr. Cyrus Thomas on Dr. Ernst 

 Foersterman, of Germany, honorary mem- 

 ber of the society, born 1818, died 1906. 

 Special reference was made to his contribu- 

 tions to the knowledge of the Maya hiero- 

 glyphics. (2) Professor W. H. Holmes on 

 Sr. Alfredo Chavero, bom in Mexico, 1822, 

 died 1906. He was equally eminent as 

 litterateur, statesman and archeologist. (3) 

 Mr. J. Mooney on Dr. Albert S. Gatschet, born 

 in Switzerland in 1832, died in Washington, 

 1907. Dr. Gatschet was for many years on 

 the staff of the Bureau of American Eth- 

 nology, and devoted himself principally to 

 the linguistics of the American aborigines, in 

 which field he was a successful pioneer. (4) 

 Dr. A. Hrdlicka presented a notice on Pro- 

 fessor Emil Schmidt, born in 1837, died in 

 1906, in Germany. Professor Schmidt's spe- 



