INTRODUCTION. XV 



looking perfectly crystallized. This was about noon. Leav- 

 ing the fish with the ice in the basin, and a fire having been 

 lighted, he after dinner, more from accident than any other 

 cause, looked at the basin, and to his astonishment saw the 

 ice in a great measure thawed, and the fish moving. At 

 midnight, when he went to bed, it was as lively a's usual. 

 Dr. Richardson, in the third volume of his Fauna Boreali- 

 Americana, devoted to Fishes, says of the Grey Sucking 

 Carp, a common species in the fur-countries of North Ame- 

 rica, that, like its congeners, it is singularly tenacious of 

 life, and may be frozen and thawed again without being 

 killed. Other instances of both extremes are detailed in this 

 volume, page 317. 



The eyes in fishes are observed to occupy very different 

 positions in different species. In some they are placed high 

 up near the top of the head, but more frequently on the 

 flattened side of the head, but always so situated as best to 

 suit the exigencies of the particular fish. The external sur- 

 face of the eye itself is but slightly rounded, but the lens is 

 spherical a structure that in a dense medium affords intense 

 power of vision at short or moderate distances, rather than 

 a long sight. When water is clear, smooth, and undisturbed, 

 the sight of fishes is very acute : this is well known to an- 

 glers, who prefer a breeze that ruffles the surface, well know- 

 ing that they can then approach much nearer the objects of 

 their pursuit, and carry on their various deceptions with a 

 much better chance of success. 



The sense of hearing has by some been denied to fishes 

 perhaps because they exhibit no external sign of ears : the 

 internal structure, however, may be most successfully demon- 

 strated in the various species of Skate, in which the firmer 

 parts of the head being formed of soft and yielding cartilage, 

 the necessary divisions may be effected with great ease. 



