THE STORY OF THE COMMON EEL 71 



Channel have much farther to go ; they have to go right 

 out to the deep water of the Atlantic, off the west coast of 

 Ireland. That is the nearest point where 500 fathoms can 

 be touched ; there is no such depth in the North Sea nor 

 in the Channel. They never come back, and no one has 

 ever yet tracked them on their journey to the deep water. 

 Yet we know that they go there, and lay their eggs there, 

 and that from these remote fastnesses a new generation of 

 eels, born in " the dark unfathomed depths of ocean," return 

 every year in their millions as little " elvers " to the rivers 

 from which their parents swam forth in silver wedding 

 dress. Soon, we have reason to hope, by the use of 

 suitable deep-sinking nets, we shall intercept, in the 

 English Channel, some of the silver eels on their way to 

 the Atlantic deeps. They must go in vast numbers, and 

 yet no one has yet come across them. How, then, do we 

 know that the silver eels ever go to this 5oo-fathom 

 abysm ? 



The answer is as follows : A very curious, colourless, 

 transparent, absolutely glass-like, little fish, 2\ inches long, 

 oblong and leaf-like in shape, has been known for many 

 years as a rarity, to be caught now and then, one at a 

 time, floating near the top in summer seas (Fig. 6). I 

 used to get it at Naples occasionally many years ago, and 

 it has sometimes been taken in the English Channel. It 

 is known by the name " Leptocephalus." Placed in a 

 glass jar full of sea-water it is nearly invisible on account 

 of its transparency and freedom from colour. Even its 

 blood is colourless. The eyes alone are coloured, and 

 one sees these as two isolated black globes moving 

 mysteriously to the right and the left as the invisible 

 ghostly fish swims around. Twenty years ago one of these 

 kept in an aquarium at Roscoff, in Brittany, gradually 

 shrunk in breadth, became cylindrical, coloured and opaque, 

 and assumed the complete characters of a young eel ! To 



