water, and that he realized these were the young eels. Aristotle's 

 ideas were soon discarded, though. As late as the seventeenth cen- 

 tury people believed that eels came out of the sea to mate with 

 snakes, or that they rubbed themselves against rocks and their 

 shreds of skin turned into young eels. Such legends emphasize how 

 puzzled people were about the sex and breeding habits of the eel. 



In 1684 a Tuscan scholar, Francesco Redi, put forward the 

 theory that eels spawned in the sea, but it was not until 1777 that 

 Professor C. Mondini, of the University of Bologna, dissected an 

 eel and discovered the ovary in it. In 1856 a German naturalist, 

 Johan Jacob Kaup, caught a small fish in the Strait of Messina and 

 named it Leptocephalus hrevirostris. He did not know that he had 

 found an eel larva. In 1874 a Polish naturalist, Simone de Syrski, 

 identified a male eel by its testes, and in 1896 two Italian naturalists, 

 Giovanni Battista Grassi and Salvatore Calandruccio, watched a 

 so-called Leptocephalus "change" into an eel. Finally, in 1904, 

 began the culminating discoveries of Denmark's Johannes Schmidt. 



Schmidt began his study of the eel by chance. He was aboard a 

 Danish research ship, the Thor, in the North Atlantic to investigate 

 the eggs and larvae of cod, herring, and other food fishes when a 

 Leptocephalus was brought up in the trawl off the Faeroes. Did eels, 

 then, spawn out in the Atlantic? Determined to get the full answer, 

 he began a long search through first one part of the Atlantic, then 



. — yauoia oy^ecimaMyaarta _J 





An illustration from Francesco 

 Redi's treatise on ells. 



Tills sixth-century B.C. vase, found at 

 Vulci, Italy, shows a Greets diver about 

 to enter the sea, probably in search of 

 sponges, which were then in common use. 



19 



