THE IMPENETRABLE SEA 



After the voyage of the females, reunited near the 

 Sargasso, the mature eels lose their appetites and their 

 golden hues. While this is happening the sexual organs 

 of the females — which have been organically perfect for 

 years — develop excessively. 



The eels have travelled at great depths to reach their 

 spawning grounds, particularly in passing through the 

 Straits of Gibraltar. They have taken about six months 

 in their journeys — both males and females, with that 

 wide interval between — from their temporary homes far 

 up the rivers. During that time their eyes have developed 

 into great lenses capable of piercing the turgid darkness 

 of the deeps, while their skins have developed a brilliance 

 amounting almost to luminescence, so that they have 

 been able to keep together — each voyager's position 

 known to the others, each migratory swarm intact. Only 

 when they reach their spawning grounds do the eels rise 

 to the surface, here, there and everywhere — each 

 migrating colony adding its numbers to the swarming 

 masses darting in and out of the weed fringes. 



They now approach the climax of their existences. For 

 this they have made the enormous two-way journey. 



Having fertilized the females the males soon die, not 

 long after their return to the Sargasso. But the females 

 survive for several years more — some of them adding as 

 much as ten years to their life-spans. They lay their eggs 

 — averaging no fewer than five million from each mother- 

 eel. But they do not lay them on the surface. The 

 mother-eels go down into the depths to give them birth — 

 down, down to an average depth of no less than three 

 thousand two hundred and fifty feet: roughly three- 

 quarters of a mile below the surface. Vastly increased 

 pressures operate at that depth. The eggs spawned by 

 the mother eels are barely a fifth of an inch in length, 

 yet what bathyscaphes they must be, tougher than steel, to 

 withstand such pressures ! From the eggs tiny creatures 

 emerge, bearing the lengthy name: ''preleptocephali". 



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