Notice of Ehrenberg' s Memoir on Microscopic Life. 297 



Art. X. — Notice of a Memoir by C. G. Ehrenberg, "On the 

 Extent and Influence of Microscopic Life in North and South 

 America.^* 



This important memoir by the illustrious Ehrenberg, is char- 

 acterized like all the preceding works of this author, not only by 

 marks of the most accurate research and indefatigable industry, 

 but by the still higher merit of far-reaching philosophical views, 

 and a just appreciation of the important bearings and applications 

 of the facts which he has brought to light. 



Believing that this memoir is one of peculiar interest to Ameri- 

 can science, we have endeavored to give in the following pages 

 as correct a view of its contents as is in our power. 



The work is divided into the following seven parts, which we 

 intend to notice in order. 1. Introduction. 2. Review of the 

 materials. 3. Enumeration of the American forms, according 

 to the dates of observation. 4. Alphabetical review of all the 

 observed and peculiar forms. 5. Characteristics of the new 

 genera and species. 6. General results of these observations. 

 7. Explanation of the plates. 



I. Introduction. — In the commencement, Ehrenberg remarks 

 that microscopic life no longer belongs to the domain of system- 

 atic zoology alone, but that its decided influence upon the inani- 

 mate nature which every where surrounds and influences us, and 

 upon the fundamental notions of life itself, have of late been re- 

 cognized, so that the subject is no longer considered merely with 

 regard to its organic and physiological bearings, but for its rela- 

 tions to the inorganic masses of the earth. There are many, 

 however, who still wish to banish these investigations from the 

 circle of strict science, and who wonder that any one should de- 

 vote so much labor to the strict examination of such inaccessible 

 and remote objects. These prejudices are compared to those 

 which prevented the importance of the first noticed electric and 

 magnetic phenomena from being appreciated, and which long 



* Verbreitung und Einfluss des Mikroskopischen Lebens in Sad und Nord 

 Amerika, Ein Vortrag von C. G. Ehrenberg. Gelesen in der Konigl. Preuss. 

 Akademie der Wissenschaften zu Berlin, am 25 Marz und 10 Juni, 1841, mit spa- 

 tern Zusatzen. Nebst 4 coloriten Kupfertabeln. Berlin, 1843. 



Vol. xlvi, No. 2.— Jan. -March, 1844. 38 



