1 84 WHAT IS A 'FEROX'? 



brown trout where they ran from 56 to 60. 

 So, too, with the number of caecal appen- 

 dages, of which Giinther assigned 43 to 49 

 to ferox, and from 33 to 47 to fario ; but 

 Day found instances of from 33 to 6 1 caeca 

 in the common trout ; so that the inconstancy 

 of these tests is at once apparent. The same 

 result is also arrived at in the next proposed 

 test, viz. the number of rays in tail and fins ; 

 as well as in another relating to the arrange- 

 ment of the vomerine teeth. In both these 

 latter cases, the results are again so varied 

 and inconstant as to make it evidently impos- 

 sible to base any safe conclusions thereon as 

 to specific differences. Colour will be at once 

 admitted by all to be a hopeless test ; all know 

 the infinite variety of coloration and marking 

 in trout from the same lake, or even from the 

 same pool of a river. We come, then, to this, 

 that after the most painstaking researches by 

 many eminent naturalists, no one constant and 

 certain difference of structural character has 

 been discovered as between the brown trout 

 and the so-called ferox. 



If one listens to gillies and boatmen no doubt 

 one will be told of various infallible methods of 

 distinguishing the ' ferok ' from the ' trout, ' but 

 the curious point is that no two of them will be 



