G. GENERAL NATURAL HISTORY AND ZOOLOGY. 269 



country, Avhich at that time was very little known, few plants 

 having been collected. Encouraged by the generous support 

 of the Chilian government, Mr. Gay undertook to prepare a 

 series of manuals first on natural history, and ultimately on 

 the geography, geology, and political history of the country. 

 This idea was steadily kept in mind by him ; and, with the as- 

 sistance of specialists in various branches, he has finally com- 

 pleted his work of thirty stout octavo volumes of text, with 

 two folios of illustrations, embracing 333 plates. The work 

 was executed in Paris under his direction, but printed in the 

 Spanish language. 6 J5, April 29, 1873, 985. 



MICROSCOPIC LIFE. 



Professor Ehrenberg has lately presented to the Academy 

 of Sciences of Berlin a compendium of the researches in which 

 he has been engaged for many years past in reference to the 

 microscopical life of the deep seas, the first report having 

 been presented in 1836 to the Academy, and supplemented 

 from time to time by additional communications. He ac- 

 knowledges very thankfully the assistance rendered by per- 

 sons of all nations, and especially in reference to the deposits 

 of California and elsewhere in North America. Some of the 

 richest material at his command was taken from the sea at a 

 depth of 20,000 feet. The total number of distinct species 

 determined by him in his various investigations amounts to 

 1435, while he has fragments of 172 others, not accurately 

 definable, but certainly additional, making a sum of 1607 

 species. He takes the occasion to contest the existence of 

 such bodies as the coccoliths, JBathyhius^ Eozoon canadense^ 

 etc. The paper concludes with a description of 299 new 

 and additional species of infusoria from various parts of 

 the world. K. Akad. Wis. Berlin ; Monatshericht^ April 25, 

 1873,251. 



FORMATIOX OF PIGMENTS BY BACTERIA. 



A thorough study of the bacteria has been made by J. 

 Schroeter, and more especially of the conditions affecting the 

 formation of different pigments, and the behavior of the color- 

 ing matter of these with reagents. As the coloring matters 

 can be extracted by alcohol, their tinctures were employed 

 for testing their chemical and physical properties. The ob- 



