82 THE SEAS 



not survive another fortnight. Also, by being laid after, 

 instead of before, the highest tide, they would be unlikely to 

 be washed out of the sand before they had fully developed, 

 since each successive high tide would be slightly lower until 

 the spring tides started once more. 



Early Life 



In most cases when first the baby fish hatch they are 

 extremely small. A young whiting (Gadus merlangus), for 

 instance, which is typical of many marine fishes, is only 

 about a quarter of an inch in length. It carries on its under 

 surface an oval sac of yolk on which it is nourished for the 

 first few days of its free existence (Plate 29). When this 

 supply is exhausted the young fish starts to feed. At this 

 stage in its life the fish is drifting freely in the water layers 

 above the bottom, and because of its small size and feeble- 

 ness it can make no headway against the currents, but is 

 carried along by them. All around is a community of other 

 drifting animals and plants, and on these the little whiting 

 makes its meals. After drifting thus for a fortnight or 

 longer the fish begins to assume its adult character and 

 appears as a true miniature of its parents. It is then about 

 an inch in length and can swim with considerable agility, and 

 seeks out new grounds in its search for food ; some kinds 

 of fish at this stage take to the sandy bottoms, while others 

 seek the rocky coves and bays along the coasts. In the case 

 of the whiting, however, a very interesting stage in its life- 

 history has yet to be passed through. The little fish seeks 

 out those big blue jellyfish, the Cyanea (Plate 30), which 

 abound at the same time of the year. These beautiful 

 animals vary in colour from a deep brown red to the most 

 heavenly ultramarine blue. They can be found of all sizes, 

 from that of a small mushroom upwards to as much as a 

 foot in diameter, and they have even been recorded in the 



