28 JOHAN HJORT. M.-N. Kl. 



have contributed their share in these instances, such as the conditions 

 of the previous Summer, the magnitude of the rainfall &c, &c, &c. 



These — non periodical — differences from year to year are, as 

 will be subsequently seen, of the greatest importance to the living 

 organisms of the Sea. 



The next Season to occupy one's attention is that of the "Winter, 

 January to March. The heavy Westerly Gales that raged during the 

 Autumn of 1893, continued throughout the Winter, and in February 

 1894, storms from the Westward were continuous, accompanied by 

 mild weather. The Surface Chart for February 1894, (D) shews that 

 the salineness of the water was than very great along the entire West 

 Coast of Norway. In the northernmost position of the stretch of water 

 that was investigated, the North Sea Water even, was met with close in 

 to the shore, this, during Summer, being, at least, 120 miles off the 

 coast. At the same time the Water of the Atlantic covered a great 

 portion of the North Sea and approached nigh to the West Coast. The 

 Bank Water was of great thickness, washing the shores of Jæderen, 

 and the whole of the Spring Herring District. On the other hand we 

 find the Baltic Current dammed up on the South East side of the 

 Skagerak and in the Christiania F"jord. The hydrographical conditions 

 continued thus on the West Coast, with trifling changes, throughout both 

 the months of February and March. 



The conditions in the deep thus correspond to the conditions in- 

 dicated on the Surface Chart (see PL II, Fig. i, and PI. IV, Fig. i). 

 In PI. IV, Fig. I, there is a representation which, in many respects, 

 reminds one of November 1893. The Bank Water and that of the North 

 Sea lie as deep layers along the land. All the lines are strongly curved 

 in towards the coast, which gives a wedge shape to the la}'ers. The 

 temperature, as in December 1894, increases downwards towards the 

 bottom. It will, however, be seen that the lines of temperature are 

 curved in towards the coast, and even if their direction is not exactly 

 parallel to those of salineness, they, nevertheless, indicate that the salter 

 layers possess a temperature correspondingly higher than the layers of 

 less saltness. The temperature 6.5 '^ to 7" is that o{W\q Atlantic Water; 

 5°, or thereabouts, is that of the North Sea Water, and about 4° is 

 that of Bank Water of a salineness of 33 per looo. It will be subsequently 

 seen that these conditions were found to be even more marked in the 

 Winter of 1895. 



As above mentioned, trifling variations in the saltness of the water, 

 occurred during the course of the Winter. On the 19th February, the 



