PARR AND SMOLTS 113 



4. That the resulting " cross " breed became indistinguishable from 

 other trout fry; and 



5. That the parent true sea-trout brood survived in a reservoir even 

 if they did not attain any great size. 



I think on the whole it is a fair and reasonable conclusion to draw 

 from the facts of the foregoing experiments, supplemented as these 

 are by the evidence of the scales of wild fish which I have just 

 submitted, that the young of the sea-trout may without discomfort 

 postpone their descent to the sea for a period of years more or less 

 prolonged according to the nature and circumstances of their fresh- 

 water environment. To carry the matter still further, it does not seem 

 to me to be extravagant to imagine, if indeed it is the case that the 

 sea-trout brood is ever indistinguishable from the brood of the common 

 trout of the district, that some of the young fish never develop the 

 migratory habit at all, or, in other words, that they remain trout. 



With the approach of the sea-trout smolt to the whitling stage the 

 facts definitely known about the fish become even less well defined. 

 No systematic examination of scales, or marking of sea-trout, have to 

 my knowledge yet been carried out, as they have been in the case of 

 the salmon, and there is no reason to believe that when they are so any 

 less interesting facts will be discovered than have been discovered with 

 reference to the life-history of the salmon. 



I have already referred to the fry and parr of sea-trout maintaining 

 an original shoal formation, and T am inclined to think that, as these 

 shoals descend from the upper waters, whether they have packed 

 together in one great body or not, they still maintain their separate 

 individuality, just as at a review of troops battalions, companies and 

 platoons may mass together at one time and separate at another. It 

 might perhaps be difficult to adduce direct evidence of this, but if one 

 accepts the theory of shoal feeding at all, there seems no very good 

 reason why the shoal which foraged for food in the fry and parr stages 



