BULLETIN OF THE UNITED STATES FISH COMMISSION. 171 



There is, moreover, a good deal of rain and snow in Iceland, and all 

 the watercourses are therefore quickly filled with water at the time of 

 the year when the current becomes stronger. Some of the water- 

 courses, therefore, have an entirely diflerent character in winter from 

 that in summer and spring. It is also well known that when there is 

 much rain even the smallest brook in Iceland becomes a rushing tor- 

 rent which is dangerous to pass. As the mass of water rises and the 

 swiftness of the current increases, the fish of course find it exceedingly 

 difficult to maintain themselves in such streams. On the other hand, 

 low water in summer will, on account of the pure and transparent 

 water of many streams, rentier it difficult lor the fish to hide Them- 

 selves. Unless they find hidingplaces on the bottom, they will be 

 come a prey to their pursuers. Many Icelanders say that, owing to 

 the clearness of the water in the fishing places, the salmon are spied 

 from some projecting rock before the net is cast. 



The nature of the surrounding country is at least of as much impor- 

 tance for the life of fish as the weather. The salmon waters of Iceland 

 •cannot expect much from the surrounding country. Vast deserts, often 

 covered by enormous masses of snow, or consisting of nothing but 

 -stone and sand, with a very scanty vegetation, are not favorable to 

 the development of animal life. The valleys are limited in extent, and 

 contain but little humus or vegetation where animal life can develop. 

 It will, therefore, also be seen that wherever the streams and lakes 

 contain many fish there will be a good deal of grass and many bushe.'^. 



The character of the Iceland streams varies a good deal. There are 

 some which flow gently through a flat country; and there are rushing 

 mountain torrents, which flow rapidly from their source to the ])lace 

 where they empty into the sea. These latter must be considered as 

 being very i^oor fish-streams. There are other streams which have a 

 rapid current, but they have along their course calm places, with a 

 gravel or sand bottom, and holes and depressions, where the fish can 

 •during the daytime hide in deep water. These streams are better 

 adapted to fish as the number of these holes increases; that is to say, 

 jf they possess other conditions which are necessary for the life of fish. 

 'The Iceland streams have one advantage over the streams in the re.^t 

 •of Europe which contain salmon, as their bed for long distances is filled 

 with lava, or as the stream has taken its course over lava-beds. The 

 fissures, holes, and steps of the lava not only furnish excellent hiding- 

 places in these clear streams, but in lava-beds springs are frequentlj' met 

 with whose temperature remains nearly the same all the year round. 

 'The importance of this circumstance in a country like Iceland need 

 hardly be explained. It may be proper, however, in this place to con- 

 tradict the common idea that warm springs are particularly favorable 

 to the development of the life of fish. Warm water may accelerate the 

 liatching process of fresh-water fish spawning in winter, but this is 

 miore harmful than helpful, because the early hatching of the salmon 



