STOKMONTFIELD EXPERIMENT. 93 



smoults, by means of the Stormontfield ponds, \ 

 and it is a far more important discovery than the I 

 parr question, which was settled by these ponds. / 

 People have been endeavouring, by all sorts of 

 theories, to account for this divided migration of 

 the smoults; some say that the males went and 

 the females stayed, others that the produce of old 

 salmon went and those of the grilse remained; 

 but the fact is, simply, that it is a habit of the 

 fish. A little reflection enables us to see that it 

 is not confined to the first migration, but is re- 

 peated on the return of the smoults as grilse one 

 year and as salmon the next, and on the return 

 of the old fish after spawning one-half coming 

 back the following summer, and the rest not re- 

 turning till the spring of the succeeding year. 

 This habit of the fish has enveloped the subject 

 in difficulty, but a clear apprehension of its truth 

 will unravel the mystery." The writer also says, 

 "We may only further remark that Mr Mackenzie 

 of Dundonnell, in his Appendix to his father's 

 book, lately published, in attempting to clear up 

 this matter, has missed the blot, and has started 

 a grievous heresy, viz., that salmon and grilse are 

 different kinds of fish. Of course, this is out of 

 the question altogether, for the same lot of ova at 



