BROOK TROUT 



tucky and elsewhere, have become so adapted to their 

 environment and to acquired methods of procuring 

 subsistence, that they seem content and attempt no 

 exit. It is not assumed that the hard lethe-Hke waters 

 of the deeper fluvial veins take any part in this econ- 

 omy of fish distribution, for assuredly no life can exist 

 therein, impregnated as they are with salts and base 

 solutions. Surface water, too, imbibes the impurities 

 of the earth or soil over which it passes, and it is only 

 when it has been filtered by percolation through sand 

 and gravel beds that it becomes as pure as when it 

 first descended in rainfall. In such pellucid fluid, 

 drawn fresh from the bosom of mother earth, the trout 

 thrive best, and in its vivifying arteries, borne under- 

 ground, the salmonidse have been passed from one 

 antipodal locality to another, at various depths, accord- 

 ing to the lay of the land. 



Distribution by other than subterranean waterways 

 is various. The presence of alien species in landlocked 

 waters is often due to overflows, freshets, and cata- 

 clysms. Transportation by migratory birds and even 

 by insects, and precipitation by cloud-bursts and water- 

 spouts, are of frequent occurrence. There is beyond 

 all an accepted theory of aerial incubation of fish ova 

 which are held in suspension in the upper atmosphere 

 until the hatched-out fry drop to earth or convenient 

 water spaces in some rainfall. One most potential 

 factor in mechanical distribution is the sturdy pelican, 

 whose range of habitat is of great extent, reaching 



