BY W. SAVILLE-KENT, F.L.S. 65 



out in my report, the temperature of the sea round Tasmania 

 is considerably higher than that of the British Seas, and more 

 nearly approximates that of the Mediterranean shores of the 

 South of France, and where repeated attempts to acclimatise 

 the salmon have entirely failed. The fry liberated in the 

 Eihone and other rivers of Lanjuedoc have thriven therein for 

 the first year or so, but after taking their departure for the 

 sea, as smolts, have failed to return as mature fish to the 

 rivers in -which they were originally born and bred. 



Regarding this question of temperature, I have instituted 

 during the maintenance of the fisheries establishment at 

 Battery Point a systematic series of diurnal observations, 

 with the view of ascertaining the average range of temperature 

 of the water in the tanks and ponds and in the adjacent sea 

 throughout the year, anticipating, as happens in the present 

 case, that such data might prove of service. These obsei'va- 

 tions have elicited the fact that the temperature of the 

 sea-water in the tanks and ponds ranges from 40deg. Fahi-. in 

 winter to 80deg. in summer, while the smaller range of from 

 SOdeg. to 70deg. represents fur the South Coast the correspond- 

 ing limit of variation in the adjacent sea. The mean isotherm 

 in either case is consequently denoted by 50deg. Fahr, 

 When recording these observations in my report, I expressed 

 regret that no siniilar data were available concerning the 

 corresponding temperatures of the British seas, as these 

 might prove of great value in the conduct of this and kindred 

 acclimatisation experiments. It so happens that in the 

 scientific journal "Nature," for June 30th, 1887, quite 

 recently to hand, an announcement is made that such a 

 series of observations is now in course of progress, under the 

 auspices of the British National Fish Culture Association — of 

 which I believe I enjoy the privilege of being a dormant 

 member — and that the results recorded will be shortly pub- 

 lished. The same announcement, moreover, contains a record 

 of observations upon temperature made during the past three 

 years in the tanks of the Association's Marine Aquarium at 

 South Kensington, and with relation more especially to its 

 influence upon the vitality of various marine fish. Although 

 no systematic table is given with this announcement, a series 

 of temperatures are recorded indicating a range of from 

 as low as 32deg. Fahr. in winter to 70deg. in summer. 

 This yields a mean isotherm for the entire year of 

 Sldeg. only as compared with that of 60deg. which 

 obtains under similar conditions in Tasmania. An an- 

 alagous comparative ratio will, it may be predicated, be 

 found to obtain in the waters of the open sea on the British 

 coast, and these figures of themselves furnish, to my mind, 

 an ample reason why, that in dealing with a species of fish so 



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