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JOHS. SCHMIDT 



In fact, the surface temperatures in the waters south and S. W of Iceland do not seem to 

 sink even in the coldest period ot the year below ca. G° whilst on the other coasts they 

 go down to 0°— 2° (see fig. 5). One shortcoming in the temperature observations given 

 on pp. 115, 116 is that they are for the surface waters. It would have been better 

 for our purpose if we could have had temperatures from for example 50 or 1Ü0 meters 

 depth, as we should tlien have come nearer to the temperatures under which the spawn- 

 ing of most of the gadoids takes place. From lack of observations however this could not 

 be done and it may be remarked that the differences between the temperatures at the sur- 

 face and those in 50 meters (cf. also p. 115) in the spring months, which are of 



Pig. 5. Observations of temperature during the first voyage of the "Thor" round Iceland in April 



1904 (of. Chart IX). The upper numbers indicate the surface temperature, the lower the bottom 



temperature. When the depths at which bottom temperatures were taken are not indicated, they 



were always less than 200, usually less than 100 meters. 



special importance here, are comparatively insignificant, so that the surface temperatures 

 may well be used for our purpose (cf. the bottom and surface temperatures for April 

 given in the list of hauls of young fishes). Further, for the years 1903 — 1905 we have 

 a large number of temperature observations in the months of April — September, both for 

 the bottom and surface waters, taken by I. N. Nielsen the hydrographer on board the 

 "Thor". The accompanying text-figure 5, representing the surface and bottom tempera- 

 tures observed during the first voyage of the "Thor" round Iceland in April 1904, i. e. 

 during the spawning time of the majority of the species, gives a good picture of the con- 

 ditions which are of importance in this connection. We see from this, that the south 

 coast of Iceland from the Horns (ca. 15° W. L.) and westwards as also the southern 



