20 MEMOIR OF 



miglit be distinguished fiora another. For more 

 than 1800 years, those who wrote upon the sub-, 

 ject almost entirely confined their attention to 

 copying, or commenting upon Aristotle. In the 

 middle of the 16th centuiy, however, Belon, Ron- 

 dolet, and Salviani returned to the true method of 

 observation, and rectifying and extending the state- 

 ments of Aristotle, conferred on Ichthyology a real 

 foundation by the description and representation of 

 a certain number of w^ell determined species. 

 Finally, Willoughby and Ray, at the end of the 

 3 7th century, attempted to arrange these species 

 according to a plan founded upon the distinctive 

 characters derived from their organization ; and 

 Artedi and Linnaeus, in the middle of the 18th, 

 completed this enterprise, by establishing well 

 defined genera, including in them various accu- 

 rately ascertained species. Since that period Ich- 

 thyology has been steadily advancing towards 

 perfection, and will continue to advance, with a 

 rapidity regulated by the ardour and sagacity with 

 which each Naturalist distinguishes what is true, 

 and publishes it, so as to ensure general appro- 

 bation. 



Aristotle, by accumulating the stores of his prede- 

 cessors, by his own extraordinary assiduity, and by 

 the not less extraordinary assistance afforded him by 

 his distinguished patron Alexander the Great, recog- 

 nized 117 species of fishes. He dwelt upon their 

 mode of life, their percgiinations, their likings 

 and dislikings, their cunning, amours, and fecun- 



