A NOTE ON THE TEXT 



The present text follows essentially that of the London edition 

 of 1859, in which Agassiz incorporated both additions and correc- 

 tions to the first American edition of 1857. One such addition, for 

 example, is Section IX of Chapter II on "categories of analogy." 

 Others, perhaps minor, consisted of details and emendations of words 

 and phrases designed to clarify specific arguments. Agassiz also added 

 further documentation in 1859, and where such data seem important 

 to his discussion they have been included here. In both editions the 

 Essay was as much a bibliography of the history and current status 

 of zoology in the form of lengthy footnotes as it was a treatise in 

 natural science. This display of sources was important to Agassiz's 

 purpose, because he wanted to show that classical biology rested on 

 firm traditional foundations. His citations, however, were often repe- 

 titive and to the modern view not always germane to the subject 

 under discussion. In such instances they have therefore been omitted 

 or shortened. Excessive punctuation has also been eliminated, and, 

 for consistency, correctness, and convenience, many footnotes have 

 been modernized. All editor's notes are enclosed in square brackets. 

 Full references to the history and status of zoological research at the 

 time of the publication of the Essay may be found in Agassiz's Bibli- 

 ographia Zoologice et Geologies (4 vols., London, 1848-1854), edited 

 by H. E. Strickland and Sir William Jardine; and in Wilhelm Engel- 

 m3.nn, Bib liotheca Historico-Naturalis (Leipzig, 1846). 



