PREFACE. ix 



most estimable Physician, ardently beloved by his 

 friends, and esteemed and venerated by the public.* 



He has limited his description of fish to the 

 varieties of the Salmo most usual in the fresh waters of 

 Europe, and which may be defined as a genus having 

 eight fins, the one above the tail fleshy, and without 

 spines. 



It is to be hoped M. Cuvier's new work on fishes 

 will supply accurate information on this genus, which 

 is still very imperfectly known. 



LAYBACH, TLLYRIA. 



Sept. 30th, 1828. 



[* That excellent man the late Dr. Babington, to whom the first 

 edition was dedicated, " in remembrance of some delightful days passed 

 in his society, and in gratitude for an uninterrupted friendship of a 

 quarter of a century." It should be kept in mind, however, that 

 it is in the last Dialogue only that the likeness is sustained. In the 

 other Dialogues, the personages are not to be identified with any 

 individuals entirely ; though here and there, in the sentiments ex- 

 pressed, and the pursuits attributed to them, features of likeness of 

 distinguished friends of the Author may be traced. This is mentioned 

 as, notwithstanding the caution' in the text, I have been more than 

 once asked who are the originals represented; the disposition on the 

 part of readers seeming to be, to consider each throughout as a 

 portrait. J. D.] 



