ECONOMIC BIOLOGY 393 



eels were born from earthworms, which were, in turn, produced from 

 mud or damp soil. The early Greeks, failing to find spawn or male repro- 

 ductive glands within the eels, named Jupiter as the father, as all children 

 of doubtful parentage were ascribed by them to this god. 



Pliny the Elder, great Roman naturalist and author, declared with con- 

 viction that eels had neither masculine or feminine sex. In accounting for 

 their multiplication he concluded that they rubbed themselves against 

 rocks, and the pieces scraped from their bodies came to life as little eels. 

 He dismissed the subject as a matter for further controversy with the la- 

 conic statement that "they have no other mode of procreation." With the 

 acceptance of such beliefs it is small wonder that centuries elapsed before 

 such theories were dispelled and such superstitions overcome. 



It was not until 1777 that the ovary of the eel was first recognized by 

 Carlo Mundini, a professor of anatomy at the University of Bologna, thus 

 definitely establishing a female sex. Ninety-five years later Reinhold 

 Hornbaum-Hornschuch announced the discovery of a male individual, and 

 the enigma that had endured for over 2000 years was on its way to being 

 solved. 



But while these discoveries partly answered the riddle of their existence, 

 where they came from and how they were produced still remained a 

 mystery. It was left to a German named Johann Jakob Kaup in 1846, to 

 find in the sea a small ribbon-like fish with a tiny head. Curious as to its 

 species, he took it home and placed it in a bottle of alcohol. After labeling 

 it Leptocephalus brevirostris, a name which exceeded the length of the 

 specimen itself, he left it there to be forgotten. 



Half a century passed before the subject emerged from the obscurity 

 into which it had been relegated. On a day in 1896 two Italians, Gracci 

 and Calandrucci, found one of Kaup's little fish in the Mediterranean, but 

 one much larger and more fully developed. This they identified as the 

 leptocephalus or larva of the edible eel that inhabited the streams of the 

 European continent. With that beginning the stage was set for a Danish 

 scientist named Johannes Schmidt. 



As Director for the Danish Commission for the Exploration of the Sea, 

 Schmidt sailed in 1906, on the first of many subsequent expeditions, to lo- 

 cate the breeding and spawning grounds of this specter of the deep. For 

 fifteen years he towed nets up and down the Atlantic, taking specimens 

 of leptocephali from the English Channel to Chesapeake Bay, and from 

 Greenland to Puerto Rico. Over this vast area he collected and correlated 

 sizes of eel larvae, carefully noting the latitude and longitude in which they 

 were obtained. 



He reasoned that the larvae were growing as they moved from the place 

 in which they were spawned toward the coast and their fresh-water homes. 

 It followed, therefore, that the smaller the larvae found in any part of the 

 ocean, the nearer such specimen must be to the place where it was born. 



