PROGRESS OF ICHTHYOLOGY. 399 



provement of the ichthyological system by Artedi 

 seems to have been a step in the progress to a 

 natural arrangement. His genera 9 , which are foriy- 

 five in number, are so well constituted, that they 

 have almost all been preserved ; and the subdivi- 

 sions which the constantly-increasing number of 

 species has compelled his successors to introduce, 

 have very rarely been such that they have led to 

 the transposition of his genera. 



In its bases, however, Artedi's was an artificial 

 system. His characters were positive and decisive, 

 founded in general upon the number of rays of the 

 membrane of the gills, of which he was the first to 

 mark the importance; upon the relative position 

 of the fins, upon their number, upon the part of 

 the mouth where the teeth are found, upon the 

 conformation of the scales. Yet, in some cases, he 

 has recourse to the interior anatomy. 



Linna3us himself at first did not venture to de- 

 viate from the footsteps of a friend, who, in this 

 science, had been his master. But in 1758, in the 

 tenth edition of the Systema Nature, he chose to 

 depend upon himself, and devised a new ichthy- 

 ological method. He divided some genera, united 

 others, gave to the species trivial names and cha- 

 racteristic phrases, and added many species to those 

 of Artedi. Yet his innovations are for the most 

 part disapproved of by Cuvier ; as his transferring 

 the chondropterygian fishes of Artedi to the class of 

 9 Cuvier, p. 71 



