34 RESULTS OF THE ATTEMPTS TO ACCLIMATISE SALMO SALAR. 



the barracouta (Thyrsifes atinij and kingfisli (Thyrsites 

 solandri), the sea-going salmouoids have swift and rapacious 

 foes to contend with ; but surely if the existing migratory 

 salmonoid of the Derweut is able to survive among them, 

 there is less fear that the normal European type of Salmo 

 salar would stand a smaller chance of escape. 



The food of our waters, suitable for the salmon, is at least 

 as rich and varied as in the waters of Groat Britain and 

 Ireland, and for this reason we may dismiss the last argument 

 in favour of the extinction theory. 



THE EXODUS THEORY. 



The exodus theory is a very old one, indeed. It was 

 advanced originally as an argument against the introduction 

 of Sahno salar to Tasmanian waters prior to the first attempt 

 made to transport live salmon ova to Tasmania. Owing to 

 the absence of any sign of the normal type of the European 

 Salmo salar it has been recently revived by Mr. Saville-Kent, 

 •who even went so far as to suggest the coast of Japan as the 

 favoured shore to which possibly our wanderers directed the 

 march of their exodus from the assumed uncongenial 

 ■warmth of the temperature of Tasmanian waters. The 

 conception of an exodus from these waters is not 

 regarded by me as unreasonable. Far from it. Never- 

 theless I am not convinced that the reasons for the exodus 

 are sufficient. Mr. Saville-Kent's suggestion that they have 

 possibly wended their way to the coast of Japan appears to me 

 to be altogether improbable and opposed to all our notions 

 ■with respect to the instinct of animals. It is conceivable, 

 although improbable, that some hereditary instinct of the 

 Tasmanian salmouoids might lead them to pierce the highly- 

 heated isotherms of the equatorial latitudes — a physical 

 barrier as compared with the w'orst possible condition of 

 Tasmania — corresponding to "jumping out of the frying-pan 

 into the fire." But if they did attemj>t this strange freak of 

 instinct, they would be guided by some notion of the natal 

 locality of their ancestors, and that would be in tlie direction 

 of the Irish coast, following the great flow of the Gulf Stream 

 througli the Atlantic, and not in the ()2>positc direction of 

 Japan. 



If the exodus was carried out in obedience to some in- 

 stinct of temperature without reference to a possible heredi- 

 tary instinct of locality, we ought to expect them to 

 travel in a southerly direction, that is, towards the latitudes of 

 the Antarctic circle. But of this jiossible migration we have 

 not the slightest evidence. On the contrary, the evidence of 

 New Zealand acclimatisation affords a complete parallel to 

 that of Tasmania. Surely we might hojie that in the most 



