1 882.] Scientific News. 173 



stream can undoubtedly be best studied at the Tortugas, though 

 important additions to our knowledge of it have been made at 

 Charleston, S. C, and at Beaufort, N. C, and along the coast of 

 New Jersey, of Rhode Island, and of Southern Massachusetts. 

 It is remarkable that the beautiful purple floating shell (Janthina), 

 which is so common at the Tortugas, should not find its way 

 further north than off Cape Hatteras, in common with other sur- 

 face forms. There are also found at the Tortugas a large number 

 of pelagic crustacese in their larval stages, among them Phyllosoma 

 and the nauplius stage of a Peneus, similar to that observed by 

 Fritz Miiller; also multitudes of young Annelids, Molluscs, 

 Actiniae, the planulae of several of the corals, Echinoderm em- 

 bryos, and a host of young pelagic fishes, among which he men- 

 tions the young of the flying fish and Leptocephali. For the 

 study of the young stages of fishes and of Acalephs the Florida 

 reefs present an unrivaled field of observation, but the number 

 of pelagic Foraminifera was unexpectedly small. 



— A work on the Gymnotus, or electric eel, was presented to 

 the Paris Academy the other day by M. Du Bois-Reymond. It 

 gives the results of recent researches in Venezuela by Dr. Sachs, 

 who went out some five years ago, at the suggestion of the Berlin 

 physiologist, to study the creature in its habitat. Dr. Sachs had 

 not completed the working up of his material for publication 

 when, unhappily, he losthis'life on a glacier in the Tyrol, in 1878. 

 His work has been extended by M. Fritsch, with the aid of 

 numerous specimens and preparations of the fish brought home. 

 Among other things, M. Fritsch has succeeded in proving, with 

 all but certainty, the development of the electric organs from 

 striated muscles by metamorphosis. Various obscure points have 

 been elucidated. 



— Mr. Alfred G. Lock, F. R. G. S., of 16 Charing Cross, Lon- 

 don, England, is preparing a book on gold mining, in which he 

 desires to describe every process and every machine of recognized 

 value in use, both in alluvial and quartz mining. He wishes also 

 to treat fully of the mineralogical associations and geographical 

 occurrence of gold in all parts of the world, and to give maps 

 showing the geographical position of all the gold fields known to 

 exist, the strike of the reefs and the rivers whose lands are known 

 to be gold bearing. The United States being the greatest gold 

 producer and its gold savin- machinery being the most elaborate, 

 he desires to give it the prominent position in the book which its 

 importance demands. He desires therefore to procure all papers, 

 reports, photographs, or other illustrations of the subject. In all 

 cases the sources of his information will be fully acknowledged. 



— The Providence Lithograph Company are about to publish 

 the Chautauqua Scientific Diagrams. Series No. 1, Geology, to be 

 edited by Professor A. S. Packard, Jr. Price $6. The series will con- 

 sist of ten chromo-lithographic charts, 33 23 inches. The sub- 



