[33] SCIENTIFIC EXAMINATION OF THE GERMAN SEAS. 557 



eye. As soon as the little fish begins to form inside the egg, the two 

 eyes are distinctly seen in the otherwise transparent egg like two black 

 dots (see Fig. XVII), and some time — according to the slower or more 

 rapid development of the fish, days or weeks — before the fish is hatched 

 the eyes are seen so distinctly that there cannot be the slightest doubt 

 that they are really the eyes of the young fish. Of the 

 body of the fish nothing can as yet be seen with the 

 naked eye, because many fish, as long as they are in the 

 egg, areas transparent as water. Other young fish, fig.xvii. 



/» ,, ., t • j_i i A fish-ena, on a dark 



for instance the pike, have even m the egg a somewhat background, magnified 

 brownish color, so that the whole fish can be distin- in u? trausl!arrat S egg 

 guished. When the eggs have reached this stage, some sMn^in^i^center 

 of them should be taken home in a flat vessel contain- theuttfefisfffs ainloat 

 ing water, which should be kept in a cool place. If it e^are seenstmnioro 

 wants only two or three days till the hatching, the ob- distinctly. 

 server will succeed in observing how the little fish act on leaving the 

 egg. As soon as an empty egg is noticed it will be easy to find the lit- 

 tle fish which has left it, as it will betray itself by its black eyes. Note 

 is taken of the time which elapses from the impregnation of the eggs 

 till the fish are hatched. This time of course varies according to the 

 temperature of the water, but as the temperature of the water at the 

 bottom at the same time in different years does not differ very much, 

 the time which has been observed will very nearly be the right time. 



As regards the actions of the young fish we know too little to give 

 any details. When beiDg hatched the abdominal cavity of most fish is 

 still filled with the matter contained in the egg (the yolk), and their 

 abdomen therefore looks somewhat bloated. As long as the fish feed on 

 this matter they take no other food, and move about very little, gener- 

 ally staying quietly on the bottom. As soon as the yolk has been con- 

 sumed they begin to seek their food. Many fish at this period of their 

 life stay in quiet waters near the surface, and have the advantage that 

 on account of their transparency they can hardly be seen by their ene- 

 mies. Gradually they begin to scatter in different directions, although 

 some kinds, such as the herrings, keep together. Gradually the scales 

 begin to appear, and the body begins to assume some color. The fish 

 then seek shelter, and are able to take coarser foodj such as the small 

 animals and plants floating near the surface of the water. For some 

 time they stay in the shallow places near the coast, and finally seek those 

 localities where the older fish live. 



x\ll the details, on which after all the correct views as to the possibility 

 of furthering the development of food-fish will depend, can only be ascer- 

 tained by more accurate observations. The proper persons to make such 

 observations at the right time will principally be found among fisher- 

 men. 



V. HENSE3T. 



