HISTOEY. 15 



himself witli systematic work. He prepared a general system 

 of fishes, in which he arranged not only those described in his 

 great work, but also those with wliich he had become ac- 

 quainted afterwards from the descriptions of others. The 

 work was ably edited and pubhshed after Bloch's death by 

 a philologist, J. G. Schneider, under the title " M. E. Blochii 

 Systema ichthyologioe iconibus ex. illustratum" (BerL 1801, 

 8vo.) The number of species enumerated in it amounts to 

 1519. The system is based upon the number of the fins, the 

 various orders being termed Hendecaptei^ygii, Decapterygii, etc. 

 We need not add that an artificial method like this led to the 

 most unnatural combinations or severances. 



Bloch's Ichthyology remamed for many years the standard 

 work, and, by the great number of excellent illustrations, 

 proved a most useful guide to the student. But as regards 

 originality of thought, Bloch was far surpassed by his con- 

 temporary, B. G. E. DE LACEPi^DE, born at Agen, in France, Laeepede. 

 in 1756, a man of great and general erudition, who died as 

 Professor of the Museum of Natural History of Paris in 1826. 

 Laeepede had to contend with great difiiculties in the 

 preparation of his " Histoire des Poissons" (Paris, 1798- 

 1803, 4to, in 5 vols.), which was written during the most dis- 

 turbed period of the French Eevolution. A great part of it 

 was composed whilst the author was separated from collections 

 and books, and had to rely on his notes and manuscripts only. 

 Even the works of Bloch and other contemporaneous authors 

 remained unknown, or at least inaccessible, to him for a long 

 time. Therefore we cannot be surprised that his work abounds 

 in all those errors to which a compiler is subject. The same 

 species not only appears under two and more distinct specific 

 names, but it sometimes happens that the author understands 

 so little the source from which he derives his information 

 that the description is referred to one genus and the accom- 

 panying figure to another. The names of genera are unduly 



