24 THE SEA-TROUT 



from the origin of other trout which people our waters. Therefore 

 the main inquiry has no occasion to turn aside to consider their case in 

 detail, although any contention that they are descendants of " land- 

 locked " fish, if capable of proof, would go far to substantiate this 

 branch of Mr. Regan's argument. 



4 Conversely, Trout exported to New Zealand have found 



THEIR WAY to THE SeA AND HAVE GIVEN RISE TO AN AnADROMOUS 



Race. 



The term " anadromous " means " migratory," but in the restricted 

 sense of migration upwards from the sea for the purpose of spawning — 

 as in the case of the salmon and sea-trout — just as " katadromous " 

 refers to migration downwards to the sea for the purpose of spawning — 

 as in the case of the eel. Mr. Regan is here on safe ground for the 

 case of the New Zealand fish is now common knowledge, mainly 

 through the instrumentality of Mr. Calderwood's admirable book, 

 " The Life of the Salmon," which was published in 1907. There he 

 tells us that " Brown trout taken from Dorsetshire to New Zealand 

 quickly acquired a migratory habit and became large silvery fish, 

 inhabiting the sea for the most part, and ascending rivers to spawn." 



5. — EsTUARiNE Trout are often intermediate in appearance and 



HABITS between THE MiGRATORY AND NON-MIGRATORY FiSH. 



I have no great belief in this so-called " estuarine " trout, and I 

 am surprised to find Mr. Regan thus countenancing the idea of its 

 existence. He seems in this to follow Mr. Calderwood who, in the 

 work already cited, states : — "In localities such as Orkney and Shetland 

 and the Outer Hebrides we have tJic csiablhhcd tidal variety which 

 has been called 5. orcadciisis \ and in the West of Ireland we have 5. 

 estuanus, the so-called slob trout. / do not agree that there is any 

 specific distinction, any more than T agree that a ferox is not a brown 

 trout." The italics, which are mine, emphasise what I think is Mr. 



