FISHES. 357 



in shallow water, may be vivified by the influence of the 

 solar rays *. At that season, some fish forsake the salt wa- 

 ter, ascend rivers, and, after spawning, retreat again to the 

 ocean. Such were formerly called Anadromi. 



The eggs of various species of fish belonging to the ovi- 

 parous order, with distinct sexes, are used as articles of 

 food. Where circumstances permit, tliey are consumed 

 while in a recent state. In other situations they are salted, 

 and form the well known article of trade called caviar. 



The chai'acters which the organs of reproduction fur- 

 nish, in the discrimination of species, have been hitherto 

 much neglected. Connected as they are with the existence 

 of the animal, and exercising a powerful controul over its 

 habits, they ought to be examined with care, and their ap- 

 pearances recorded in detail. 



Few accurate observations have been made to determine 

 the age of fishes. The element in which they reside, is 

 supposed to preserve them from the pernicious influence of 

 sudden changes of temperature ; the slowness of the pro- 

 cess of ossification, the coldness of their blood, and the 

 tardiness of all their primary movements, are considered as 

 indicating a lengthened existence. Accordingly, we find 

 the age of the carp has been known to reach to 200 years, 

 and of the pike to 260. The marks, however, by which the 

 age of fishes may be determined, remain yet to be discovered. 



Fishes are greatly tormented with intestinal worms. The 

 common stickeback may be quoted as a remarkable instance. 

 Its death is often occasioned by the increase of the Twnia 

 sollda of Gmelin ; and it is even supposed, that this fatal 



* The practice of cutting the sea-weeds for the manufacture of kelp, has 

 deprived many species of a suitable situation for the deposition of the 

 spawn, and the fry of the requisite protection. Hence the universal com- 

 plaint, along the shores of Scotland, that fish arc now less abundant than 

 formcrlv. 



