158 MARKETABLE BRITISH MARINE FISHES 



found that egi;s kept in water at 32° took forty-sev^cn days to 

 hatch, and many of the larvae were deformed ; at 33° and 34° 

 however they took only a little less time, and were uninjured. 



The newly hatched larva (Fig. 85) is 5*3 mm. (over V inch) in 

 length, and is more developed than the young of fishes which are 

 hatched from buoyant eggs. The eyes are black, and the mouth 

 is open, but the latter is on the lower surface of the head and 



Fig. 84. — Egg of the Herring, the embryo about half developed, alive, 

 and magnified. 



the jaws are not developed. The gill-slits are also open, but 

 there is no gill-cover. The intestine extends back a long way 

 behind the yolk-sac, the vent being near the end of the tail. The 

 fin-membrane extends along the back and round the end 

 of the tail, and also between the vent and the yolk-sac. There 

 is very little pigment on the body, only a few black specks, none 

 on the fin-membrane. After the yolk-sac is absorbed the little 

 fish continues for some time to grow in length without becoming 

 much thicker. The jaws develop, and by the time the larva is 



