THE SALMON FAMILY„ 263 



Even as late as NovemlDer and December, and the Janu- 

 ary and February following, a few fish continue to run 

 which have been usually considered as " barren " — without 

 capability of spawning ; but this notion has been proved by 

 Mr. Pfennell * to be erroneous, as upon dissection he found 

 that the females had ova in them perfectly developed, al- 

 though not larger than mustard-seed, whilst in the males 

 a thin thread of milt was always discernible. These fish, 

 of which many ascend the Tay in November and the three 

 following months, remain nearly a year in the fresh waters 

 before spawning, and although their colours gradually 

 become darker in consequence, they are to all intents and 

 purposes " clean fish " f, and are exceedingly good eating. 



The appearance of these so-called barren Salmon at a 

 time when most fish are spawning, or are just recovering 

 from the process, illustrates what I believe to be the most 

 important fact connected with the history of the Salmon, 

 and one which does not appear to have been hitherto 

 understood, although following as a natural corollary to 

 the propositions of Mr. Ffennell, and hinted at by Mr. 

 Brown in his account of the Stormontfield experiments, 

 viz. that the principle of a divided migration is not con- 

 fined to the Parrs on going to the sea, or to the Smolts 



* See Appendix to Report of Commission of House of Lords on the 

 Salmon Fisheries. 



t " Clean fish " is used as the antithesis to " foul fish " — a term 

 applied to all Salmon which have either not recovered from the effects 

 of spawning, or in which the roe or milt has arrived at a considerable 

 degree of maturity. 



