70 SCIENCE FROM AN EASY CHAIR 



seven years old and over, put on, as it were, a wedding 

 dress. They become " silver " eels, and descend the rivers 

 to the sea. There they produce their spawn. The young 

 eels thus produced, when only 2 inches long, leave the 

 sea. Every year they ascend the estuaries and rivers of 

 Europe as " elvers " in enormous numbers, their procession 

 up the rivers being known as " the eel-fare." 



Some eels, shut up in moats and ponds, never escape 

 they become more or less " silver " and restless, but fail 

 to get away. Others crawl up the banks in wet, warm 

 weather, when the ponds are full to the brim, and over 

 the meadows. They are found sometimes on their journey 



when they 



"... have to pass 

 Through the dewy grass," 



and so to the river, and on to the marriage feast in the 

 deep sea. The fact is, that usually eels inhabit in large 

 numbers the rivers and streams, and have no difficulty in 

 getting down to the sea when they are adult. Those who, 

 as young elvers, have wandered far off into sunken ponds 

 and reservoirs, are eccentric spirits who have lost the 

 normal way of life ; like fellows of colleges in the old 

 days, they have cut themselves off from the matrimonial 

 " running down," but they have compensations in quietude, 

 abundant food, and a long life. 



We now know where the silver eels go when they run 

 down the rivers. They go into the sea, of course ; but we 

 know more than that. It has now been discovered that 

 they make their way for many miles along the sea-bottom 

 in some cases hundreds of miles to no less a depth 

 than 500 fathoms. In the Mediterranean they don't have 

 very far to go, for there is very deep water near the land, 

 and Professor Grassi found evidence of their presence in 

 the depths of the Straits of Messina. But the eels of the 

 rivers which empty into the North Sea and English 



