[3] EGGS OF THE PLAICE, FLOUNDER, AND COD. 429 



succeeded on the 14tli of May in getting a few specimens of young fisli. 

 These had already lost their symmetrical shape, and measured about 12 

 centimeters in length. They had been found amoug the algse a short dis- 

 tance beyond the mouth of the bay. If nothing else was gained, we had 

 at any rate discovered a place where search for such fish might be made. 



The experiments in developing eggs did not succeed. The vessels in 

 which I had placed them were attached to poles and sunk in tbe bay, 

 but the motion of the waves had thrown the eggs too violently against 

 the sides of the vessels, and from this cause probably they had perished. 



Therefore, the following year it was our purj^ose to obtain the eggs 

 which might be freely scattered over the bottom. The eggs will slip 

 through the meshes of a common dredge, and by a net with narro!*w 

 meshes the bottom cannot be sufficiently scoured, because the net will 

 be filled with particles of mud from the bottom as soon as it becomes 

 the least embedded in the ground, or is dragged over a soft bottom. 

 It is important that the eggs should, if possible, be obtained by small 

 quantities at a time. For this purpose we used the contrivance shown 

 in the accompanying illustration. 



a. 



Fig. 1. — Dredges for collecting fish eggs. 



At the distance of about a foot from the bag of a common dredge (A), 

 a second light dredge with very narrow meshes (B) is fastened to the 

 first by three cords ; it rests on a bent piece of thin tin (6), in such a 

 manner that the opening of the net is entirely raised from the bottom, 

 and does not touch it at all. Anj light objects stirred up from the bot- 

 tom by the preceding dredge, if small enough to pass through its meshes, 

 are caught by the tight bag of the second net, whilst heavy objects, 

 such as sand and small stones, fall to the ground before the opening of 

 the second net. This contrivance has been found exceedingly practical 

 in fishing lower forms of animals. 



In 1881 only dead eggs were caught in the inner bay, which i)robably 

 came from the numerous plaice and cod caught during that year. 



It was not until we reached buoy No. 1, outside the mouth of the bay, 

 at a distance of 18 kilometers from the city of Kiel, that at every haul, 

 going to a depth of 18 and less meters, we caught, close to the deep 

 channel of the Kiel bay, which begins here, a number of eggs which 

 floated about freely and did not adhere to any objects. Sometimes we 

 found them singly, and occasionally in clusters of 30 to 50. From this 

 circumstance we concluded that these eggs, which first were found on 



