SCIENCE. 



[N. S. Vol. XXI. Xo. -546. 



ceived renewed study from the standpoints of 

 coniijarative anatomy and comparative em- 

 bryology by some of our ablest morphologists, 

 but none of these researches appears to give 

 adequate attention to the recent phases of the 

 doctrines of nerve components and the func- 

 tional subdivision of the nervous system. 

 Professor Johnston reviews this literature ex- 

 haustively from the new point of view and in 

 the light of his own researches (partly not 

 before published), discussing the problems of 

 head morphology and segmentation with illus- 

 trative diagrams and tabular summaries. The 

 phylogeuy of the organs of special sense is 

 discussed fully with reference to their primi- 

 tive segmentation and their derivation from 

 more primitive types of sensory mechanisms. 



Bird-Lore for May-June contains the fol- 

 lowing leading articles : ' The Motmots of our 

 Mexican Camp,' C. "William Eeebe ; ' Some 

 Early American Ornithologists, II., William 

 Bartram,' Witmer Stone ; ' The American 

 Bittern at Home,' E. G. Tabor; tenth paper 

 on 'The Migration of Warblers,' W. W. 

 Cooke; Notes and Book News and Reviews. 

 The section devoted to ' The Audubon So- 

 cieties ' contains much encouraging informa- 

 tion in regard to bird protection, but shows 

 that continued effort is still necessary, particu- 

 larly in the case of game birds. The final 

 paper is a ' leaflet ' devoted to the Barn Owl 

 and showing his good qualities as a mouser. 



The Popular Science Monthly for June 

 contains papers by the following contributors: 



William A. Locy : ' Von Baer and the Rise 

 of Embryology.' 



Edward S. Holdex : ' Galileo.' 



Arthur H. Daniels : ' The Teaching of Logic' 



Charles A. White: 'The Mutations of Lyeo- 

 persicum.' 



Henry S. Williams : ' What is Research ? ' 

 W. J. Beal: 'Plants that Hide from Animals.' 



SOCIETIES AND ACADEMIES. 



THE geological SOCIETY OF WASHINGTON. 



The 168th meeting of the Geological So- 

 ciety of Wa.shington was held on April 26 at 

 the Cosmos Club. 



As informal communications, Mr. L. C. 

 Gratoii exhibited photographs of Taughannock 

 Falls, New York, and Dr. F. E. Wright ex- 

 plained a new method of determining the opti- 

 cal character of minerals. The regular pro- 

 gram included the following papers : 



The Ore Deposits of the Ouray Quadrangle, 

 Colo.: Dr. J. D. Irving. 



The ore-deposits are located in a small area 

 of about three and one half miles square in the 

 precipitous country in the near vicinity of 

 Ouray, Colo. 



The rocks of the region comprise a series of 

 sedimentaries ranging in age from Algonkian 

 to Cretaceous, with included porphyries, while 

 the higher hills are capped by thick beds of 

 volcanic tuff. 



The ores are classified as silver-bearing 

 fissure veins, gold-bearing fissure veins, re- 

 placement deposits in quartzite, replacement 

 deposits in limestone. 



The silver-bearing fissure veins penetrate 

 the sedimentaries and pass occasionally up- 

 ward into the volcanic tuff. They carry 

 galena, tetrahedrite and some other sulphide 

 in a gangue of barite and quartz. Replace- 

 ments of limestone occur where beds of this 

 rock are penetrated by the fissures. The 

 silver values are present in the tetrahedrite. 



The gold-bearing fissure veins are associated 

 with intrusive dikes of monzonite-porphyry, 

 and contain chiefly auriferous pyrite with 

 some chalcopyrite in a gangue of quartz and 

 crushed country rock. 



The replacement deposits in quartzite are 

 flat shoots of gold-bearing pyrite with a little 

 galena and other sulphides which have been 

 deposited in quartzite. It is thought that they 

 owe their origin to alkaline waters tliat have 

 ascended to the quartzite through minute fis- 

 sures. The quartzite is fully replaced only in 

 the neighborhood of the fissures and is sur- 

 rounded by empty solution cavities in the 

 quartzite resembling those usually encountered 

 in the limestone beds. The ores range from 

 $30 to $600 in value. 



The replacement deposits in limestone are 

 of three kinds. One is in the limestone beds 

 along the courses of the normal fissure veins 



