36 AMERICAN FISHES. 



portion of tlie animal creation, than in many previous centuries ; and 

 although much yet remains, infinitely more, doubtless, than has been 

 done, still we have very recently attained much certain knowledge 

 regarding several of the most interesting families ; we have arrived at 

 results which, by simple deduction, show us how we may hope to arrive 

 at more, having now obtained data wherefrom to advance and discover 

 the process by which to do so. 



The means by which thus much has been accomplished, may be 

 described briefly, as the taking nothing for granted, assuming nothing 

 on hearsay beyond facts, and on investigating everything carefully and 

 painfully, not following too readily preconceived opinions, nor being 

 misled by mere external and superficial resemblances, but being guided 

 by comparison and experiment, as founded in a great degree on ana- 

 tomy and osteology. 



In the examination and comparison of fishes, the clear understand- 

 ing of a few simple facts, which it is necessary to observe and record, 

 will enable any sportsman to describe any supposed new variety or 

 species, with such accuracy as to render his description of the highest 

 value for scientific purposes ; to make it, in short, such that a naturalist 

 shall be justified in pronouncing positively thereupon as to the genus, 

 species, sex, and perhaps age, of the variety described or discovered. 



The first point to be observed is the 'nature of the fins, as hard-rayed 

 and spiny, as in the Pearch, the Bass, and others which it is needless 

 here to enumerate; or soft-rayed and flexible, as in the Pike, the 

 Salmon, the Carp, and many more. The second, is the position of the 

 fins; and to elucidate this point to the unscientific reader, I here 

 subjoin an outline with references, to render this method of examina- 

 tion comprehensible and easy of acquisition to anybody. 



The subject of this outline is the young of the Lake Trout, Salmo 

 Trutta Lin. of the European continent. This figure, which is taken 

 by permission from Mr. AGASSIZ' fine work, Histoire Nat u relic, des 

 Poissons d^Eau douce de ISEurope Centrale, represents a young Sal- 

 mon Trout, taken in the lake of Ncufchatel, at the end of summer, 

 less than a year old. The lower figure gives the outline of the same 

 fish, as seen from above. Other cuts of the same simple description 

 will show the formation of the head, the gill-covers and the dental 



