108 MARVELS OF FISH LIFE 



hundreds of other forms of minute marine life, a few 

 perfectly transparent spherical globules, about one- 

 twentieth of an inch in diameter. The microscope 

 showed these globules to be fish eggs. As the season 

 advanced, the number of these eggs in the sea greatly- 

 increased, and by March they were more abundant than 

 any other form of marine life found near the surface 

 of the water. So abundant did these eggs become, that 

 on a calm day they could be seen from a boat floating 

 as a thick layer. 



By the end of May, the sea swarmed with millions 

 of transparent little cod, about a third of an inch in 

 length. These fish could be seen feeding on the minute 

 crustaceans near the surface. By the end of June the 

 little cod were about an inch in length, and soon after 

 this the majority of them disappeared. Sars again 

 found them early in July, sheltering under large jelly 

 fish. The young cod, which were now about an inch 

 and a half in length, were found to be full of crustacean 

 parasites, known as medusa-fleas, similar to those on 

 their floating shelters. No doubt young cod gather 

 together under the jelly fish in this manner in order to 

 obtain this parasitic food, but incidentally this method 

 of feeding helps to conceal the young fish from attack. 



Towards the end of July young cod leave the shelter 

 of the jelly fish and take up their abode in the seaweed 

 amongst the rocks. In a year's time these fish have 

 grown to six or seven inches in length. During their 

 second summer the young cod still keep amongst the 



