Makch 7, 1902.] 



SCIENCE. 



389 



THE GEOLOGICAL SOCIETY OF WASHINGTON. 



At the meeting of the Society on February 

 12 the first paper was by Mr. G. P. Merrill 

 and was entitled, 'Eutile Mining in Virginia.' 

 Mr. Merrill called attention to the fact that 

 recent experiments in the making of cast iron 

 and steel had called for titaniferous aUoys. 

 As a result of this, a rutile deposit, situated 

 on the Tye Eiver, near Roseland post-ofEce, 

 Nelson County, Va., had been opened up. The 

 country rock is a strongly foliated g-neiss trav- 

 ersed by dikes of hypersthene diabase. The 

 rutile occurs associated with a coarsely crystal- 

 line quartz feldspar rock, the exact nature of 

 which has not yet been made out, but which, 

 from the size of the deposit and its crystalline 

 nature, is judged to be eruptive. The rock is 

 a coarsely crystalline aggregate of potash and 

 soda-lime feldspar, of a light gray color, 

 through which are disseminated small rutiles. 

 With it is associated bluish, opalescent 

 quartz, which occurs under such conditions as 

 to suggest that it is not the result of primary 

 crystallization. 



In a brief paper entitled, 'Notes on the 

 Geology of the Klondike,' Mr. W. C. Menden- 

 hall sketched the general relations of the rocks 

 in the mining district tributary to Dawson, 

 so far as they are known, and outlined the 

 relations borne by the gold-producing creeks 

 to the geology. A brief account of the occur- 

 rence of the gold in the present stream gravels 

 and on the terraces which mark older stream 

 courses was given, and the probability that 

 the gold was derived from stringers or lenses 

 in the schists which are cut by the streams 

 and has not been transported for any distance 

 was brought out. 



Mr. Arthur C. Spencer presented a paper on 

 'The Manganese Ores of Santiago Province, 

 Cuba.' All the manganese produced in Cuba 

 has been shipped from Santiago, the chief city 

 of the easternmost province. The deposits are 

 found back from the coast and are distributed 

 over an extended region. In their mode of 

 occurrence they are replacements of limestone 

 and of calcareous green-sands in localities that 

 have suffered disturbance and folding. From 

 the association of jasper, also replacing cal- 

 careous rocks, it is believed that hot circulat- 



ing water has been active in the formation of 

 these valuable deposits. 



Mr. Whitman Cross spoke of the evolu- 

 tion of ideas on systematic petrography in 

 America, referring to the conservative attitude 

 of geologists, presented in text-books, as repre- 

 sented by J. D. Dana; to the propositions for 

 the classification of volcanic rocks presented 

 by Clarence King, regarding them as the only 

 true igneous rocks; and to the proposition 

 made by M. E. Wadsworth. Concerning the 

 part played by petrographers of this country 

 in shaping existing systems, it was pointed out 

 that while but few original proposals of note 

 had been made, the results of the many in- 

 vestigations had almost unconsciously caused 

 a gradual evolution of opinion, even without 

 the influence of any American system. 



Mr. E. H. Chapman exhibited some interest- 

 ing photographs showing stratification in mine 

 dumps. 



Alfred H. Brooks, 



Secretary. 



BIOLOGICAL SOCIETY OF WASHINGTON. 



The 349th meeting was held on Saturday 

 evening, February 8. 



Dr. C. A. White gave a review of 'The 

 Mutation Theory of Professor de Vries,' giv- 

 ing an outline of his experiments with various 

 plants which had led to his conclusion that 

 evolution was not always a slow process, but 

 that under certain conditions might take place 

 rapidly, and that there was a period in the 

 growth of a race of plants or animals when 

 it was particularly susceptible to external in- 

 fluences. 



The paper will appear in the next 'Eeport' 

 of the Smithsonian Institution. 



Henry W. Olds presented 'Some Deductions 

 from the Study of Bird Songs,' prefacing his 

 remarks with the statement that the con- 

 clusions he was about to present were merely 

 tentative, but, if corroborated by subsequent 

 investigations, of much importance from their 

 bearing on the question of the evolution of 

 music. Music, he stated, seems to be popu- 

 larly regarded as artiflcial and musicians ap- 

 parently consider it largely, if not entirely, 

 governed by fixed laws, while certain students 



