THE HERRING FAMILY 159 



,", inch long fine fin-rays appear in the tail and in the middle of 

 the back, indicating the dorsal fin. The ventral and pelvic fins 

 appear later. After the larval fin-membrane has disappeared, 

 when the little fish is i^ to if inches long, although the bones 

 of the head are well developed the body is still slender and very 

 delicate and transparent, having neither scales nor silvery layer 

 in the skin. 



The transformation of the larval herring, or the most import- 

 ant changes, take place in the case of the spring herring of the 

 Baltic, and probably in other spring races, between the ages of 

 two months and three and a half months, and between the lengths 

 of i inch and ii inches. The change consists in the develop- 

 ment of the scales and silvery layer in the skin, and the growth 

 of the body in depth and thickness. During this change the 

 dorsal fin passes forwards nearer to the head. When the fins 



FIG. 85. Larva of the Herring newly hatched, alive and magnified. 



first appear the dorsal is considerably behind the pelvic, and 

 nearer to the ventral than in the adult fish, but after the change 

 the commencement of the dorsal is in front of the pelvic or 

 hinder pair of side fins. 



The most accurate and complete observations on the history 

 and growth of young herring are those made by the German 

 naturalist Meyer in the Baltic in the neighbourhood of Kiel. 

 An account of these will first be given here, and then some 

 observations on young herring in our own country will be de- 

 scribed and compared with them. 



The spawning of the spring herring at the mouth of the river 

 Schlei begins at the end of March, and takes place principally 

 in April and May. At the end of May, 1874, numerous young 

 (larvae) derived from this spawning were netted in the Schlei, and 

 were found to be I inch to ii inches long, on June roth others 



