THE IMPENETRABLE SEA 



You may examine a specimen left in a pool on the 

 shore, probably the handsome Aurelia aurita, with its four 

 violet loops clearly visible within its almost transparent 

 body. The loops are the creature's organs of reproduc- 

 tion, but its anatomy, habits and life story seem common- 

 place enough compared with those of the man-of-war, so 

 that Aurelia aurita seems a creature of this world, and the 

 man-of-war a monster from another — yet they are close 

 relatives among the myriads of living creatures which 

 throng the world's shores and coastal waters. 



Nothing in nature is commonplace. Darwin, who spent 

 years of his life studying the earthworm, confessed that 

 he knew very little about it. Lubbock devoted most of 

 his life to the study of ants, bees and wasps, yet frankly 

 admitted his ignorance of them. The life story of the 

 Aurelia aurita is simply told. But it is only superficially 

 simple. You might spend a lifetime studying it and still — 

 like Darwin and the earthworm — know very little about 

 it. 



It is typical of the life stories of numerous jelly-fishes. 

 The creatures are male and female, but their breeding 

 process superficially seems more plant-like than that of 

 other members of the animal kingdom. 



The male jelly-fish release their sperm into the water, 

 and the females, swimming nearby, contact it and are 

 fertilized. The mother Aurelia aurita is much more 

 devoted to her babies than most jelly-fish : she retains her 

 tiny eggs in a membraneous "pocket" until they hatch 

 out. They have no resemblance to their parents as they 

 drift about and eventually fasten themselves to rocks on 

 the sea-bed near the shore. Time passes and each infant 

 gradually assumes the appearance of a tiny sea-anemone 

 with a mouth that never closes, and four rudimentary 

 tentacles grouped around it. These lengthen and increase 

 in number until it possesses thirty- two writhing feelers. 

 Side-shoots are then developed until the creature looks 

 more like a vegetable than an animal, and remains like 



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