404 The History of Ichthyology 



work on special groups, on local faunas, or on particular branches 

 of the subject of ichthyology. These lines of study were made 

 possible by the work of Cuvier and Valenciennes and especially 

 by that of Dr. Gunther. 



Before taking up the students of faunal groups, we may, 

 out of chronological order, consider the researches of three 

 great taxonomists, who have greatly contributed to the modern 

 system of the classification of fishes. 



Louis Agassiz (born at Motiers in western Switzerland in 

 1807 ; died at Cambridge, Mass., in 1873) was a man of wonder- 

 ful insight in zoological matters and possessed of a varied range 

 of scientific information, scarcely excelled in any age — intellec- 

 tually a lineal descendant of Aristotle. His first work on fishes 

 was the large folio on the fishes collected by Jean Baptiste Spix 

 (1781-1826) in Brazil, published at Munich in 1827. After 

 his establishment in America in 1846, soon after which date, 

 he became a professor in Harvard University, Agassiz pub- 

 lished a number of illuminating papers on the fresh-water fishes 

 of North America. He was the first to recognize the necessity 

 of the modem idea of genera among fishes, and most of the 

 groups designated by him as distinct genera are retained by 

 later writers. He was also the first to investigate the structure 

 of the singular viviparous surf-fishes of California, the names 

 E)i!biotoca and Holconotiis applied to these fishes being chosen 

 by him. 



His earlier work, " Recherches sur les Poissons des Eaux 

 Douces," published in Europe, gave a great impetus to our 

 knowledge of the anatomy and especially of the embryology 

 of the fresh-water fishes. Most important of all his zoological 

 publications was the " Recherches sur les Poissons Fossiles," 

 published at Neufchatel from 1833 to 1843. This work laid 

 the foundation of the systematic study of the extinct groups 

 of fishes. The relations of sharks were first appreciated by 

 Agassiz, and the first segregation of the ganoids was due to him. 

 Altliough he included in this group many forms not truly related 

 either to anything now called ganoids, nor even to the extinct 

 mailed forms which preceded them, yet the definition of this 

 order marked a distinct step in advance. 



The great, genial, hopeful personality of Agassiz and his 



