[29] SCIENTIFIC EXAMINATION OF THE GERMAN SEAS. 553 



with little trouble and loss of time. When passing over so-called codfish 

 banks, such as are formed by the codfish whilst spawning, the plummet 

 will scarcely reach the bottom, because it falls from fish to fish. When 

 the herrings on their way to the spawning places pass through narrow 

 channels like the Schlei, they can be easily speared or caught with a 

 hook, as the water is completely filled with them. If the herrings 

 spawned in pairs, the method of fishing would have to be different from 

 what it is now, and the fisheries would scarcely be profitable. 



The dangers to which the eggs are exposed differ according to the 

 manner in which they are laid. Eggs floating about in the water run the 

 risk of being cast ashore and perishing there. The eggs are therefore 

 laid not too close to the coast, and as the waves move floating objects 

 but very slowly, and as the wind does not hurt the eggs, which are so 

 heavy that they protrude but little, and not at all during stormy 

 weather, fewer eggs than might be thought perish from this cause. 

 The eggs are the favorite food of numerous animals. Among the fish 

 the eel and stickleback are notorious for their voracity. Eggs which 

 float about freely have not much to fear from such enemies, for they 

 swim about singly, and are so transparent that they cannot easily be 

 seen. Large animals cannot fish for such eggs, and only occasionally 

 they are pierced and devoured by the small crustaceans which float 

 near the surface. The case is very different with those eggs which lie 

 at the bottom. If the fish spawn in pairs the eggs lie in heaps in dif- 

 ferent places, and if an eel or stickleback finds them, he will devour all 

 or leave but very few. But as the fish spawn in different and widely 

 scattered places the eggs are hard to find, and whole heaps of them 

 thus escape their enemies. 



Mold is a dangerous enemy to fish-eggs. It will go through the eggs, 

 and going from egg to egg quickly destroy their life. Whenever at- 

 tempts have been made to develop fish-eggs in aquaria, the eggs have 

 almost without exception grown moldy before the young fish were ready 

 to leave the eggs. In the open air, or in water which has waves, this 

 danger is not so great ; it seems that the germs of the mold, of which 

 there are always many in the water, find no time to stick to the eggs, 

 but are constantly washed away by the waves. I have occasionally ob- 

 served moldy fish-eggs in shallow places near the shore where there was 

 stagnant water, but on the whole this kind of destruction is not of very 

 frequent occurrence in the sea. If the eggs are scattered, as is the case 

 with the herring eggs, they are distributed all over the bottom of the 

 sea, and cling to any objects or plants which come in their way. Here 

 is a rich harvest field for egg-devouring animals, and the only drawback 

 is that the eggs are so scattered. But on this very account it is diffi- 

 cult to destroy large masses of them, and some will invariably escape. 

 I am astonished that I have never seen it mentioned that eels are fre- 

 quent in such places, for it would certainly seem highly probable that 

 such an "egg-field" would attract them. The fishermen do not at all 



