STOEMONTFIELD EXPERIMENT. 53 



Allowing for what were taken with the marks 

 and not reported, we may estimate at least forty, 

 so that, taking them as one for every 100, would 

 give 4000 grilses "having been added to the 

 stock in the river from the breeding ponds." 

 We are unable to give the date when taken, and 

 weight of the other grilse seen by Mr Buist, as 

 he has mislaid his jotting. The fish that re- 

 mained in the pond by the end of the year, 

 although healthy, did not increase much in size ; 

 but many of the male parrs were full of milt, and 

 great numbers of the fry were still very small 

 not being much above three or four inches in 

 length. To account for the great difference in 

 size, it was thought that the large fish prevented 

 the weaker and smaller from getting their regular 

 share of the food, but, at the exodus of the 

 smoults, we observed, and our observation has 

 since then been confirmed, that both large and 

 small alike take on the smoult dress when the 

 migration time arrives, and those parrs that re- 

 main are composed in the same ratio of large and 

 small. It was then conjectured that the small 

 were the produce of two grilses, or of a grilse and 

 salmon; but, as we proceed, we shall see that 

 this conjecture was equally at fault. 



