TINKER. 179 



strongly many fishes, and this family in ])iirti(Mihir, arc disposed 

 to assume tlieir tints from the nature of tlie uround in wliich 

 they live, a fact well known to fishermen, and Ovid, in ancient 

 times, when he says of another inhabitant of the waters, 

 (the Polypus) — 



"Sub lege loce mutatquc cnlorem;" 



"The place's law compels U< cliangc its tints." 



Nor is the presence of a ridge or scales near the tail a snrer 

 mark of the distinction of species, for among the three-spined 

 species, this ridge, naked or plated, is found to occur indis- 

 criminately. 



With regard to the number of dorsal spines, above referred 

 to, Nilsson says that they are about ten in number; that this 

 fish is about an inch and a half or two inches in length, which 

 shews it larger than with us; and that it is common in all the 

 waters of Scandinavia. The threc-spined species, he says, is 

 even found within the arctic circle. 



