234 GEOLOGY. 



mineralogists have never found it difficult to explain its formation by 

 purely inorganic forces. Perhaps the question has never been so near 

 settlement as when, shortly ago, Karl Mobius, jirofessor of zoology at 

 Kiel, published a most exhaustive study of specimens obtained in part 

 from the original describers. He concluded, after careful microscopic 

 study and comparison with assumed allied forms, that there is nothing 

 to justify the supposition of its organic nature. His opinion was, in- 

 deed, not of sufficient weight" to con%'ince those of fixed opposite opinion, 

 neither will probably agreement be ever reached in this generation, for, 

 as the believers in it say, the evidences are before us and we have but 

 to form our judgment. 



SUBMARESTE GEOLOGY. 



Mr. Alexander Agassiz, incidentally' to his work of dredging in the 

 deep waters of the Atlantic, has found that shallow waters connect the 

 West Indian islands with the South American continent, and this, 

 together with the notable fact that the flora and fauna of these islands 

 are related to those of Central America, and not to those of the southern 

 United States, indicate that in past time these were very probably a 

 part of the southern contiuent. This may be considered as another 

 addition to geology, gained by the investigation of the ocean's bottom, 

 so many of which were gained by the British expeditions. Professor 

 Verrill has found tertiary fossiliferous rocks by dredging off the north- 

 ern coasts. 



CHEMICAL GEOLOGY. 



The work upon general and chemical geology by Justus Roth, one 

 volume of which is now issued, will be a most important addition to 

 literature. This first volume treats of the formation and decomposition 

 of minerals, of spring, river, and sea water, and their depositions. It 

 contains in abstract, with references, all the work which, up to the pres- 

 ent time, has been done upon these subjects, and contains, besides, many 

 original contributions. Indeed, this work promises in all its parts to 

 form a kind of compendium of the science, which is much needed. 



AMERICAN ASSOCIATION. 



The American Association for the Advancement of Science met this 

 year at Boston, and the number of papers presented upon geological 

 and mineralogical subjects was so large that a permanent subsection 

 was organized to accommodate those especially interested in these sci- 

 ences. The election also of Professor Brush, one of oui' most distin- 

 guished mineralogists, to the office of president of the association is an 

 indication of the appreciation by the association of labors in these 

 departments. 



