DEVELOPMENT 337 - 



kept the larvae alive for about two weeks. Next, two other 

 Italian investigators, Grassi and Calundruccio, made a thorough 

 study of the Leptocephali of the Straits of Messina, and were 

 able to trace the transformation of several kinds of larvae into 

 their respective species of Eels. They showed beyond any doubt 

 that the larva which had been named by Kaup, Leptocephalus 

 brevirostris, was the young of the Common or European Fresh- 

 water Eel (Anguilla anguilla), thus establishing that fresh-water 

 as well as marine forms pass through the same larval history. 

 They concluded that the European Eel bred in deep water 

 near the coast, and that the larvae lived at considerable depths, 

 being brought to the surface in the Straits by the agency of the 

 strong currents and whirlpools prevaihng there. This explana- 

 tion was ingenious, and not surprising in view of the data 

 at their disposal, but, as has been already pointed out {cf. p. 289), 

 was still far from the truth. Finally, the whole Hfe-history of 

 the European Eel has been elucidated by Dr. Johannes Schmidt, 

 who has traced the larvae on their long journey across the 

 Atlantic, and has examined them at almost every stage of their 

 development. He has also paid considerable attention to the 

 American Eel [Anguilla rostrata), and is at present engaged in 

 investigating the life-histories of some of the species inhabiting 

 the Indo-Pacific region. Curiously enough, the egg of the 

 European Eel has yet to be described, but four years ago an 

 American expedition to the Atlantic procured five eggs which 

 were hatched out in the laboratory, and these are confidently 

 believed to be those of the American species. 



The larval history and metamorphosis of the European Eel 

 may be briefly summarised. The breeding-grounds lie in the 

 Western Atlantic, south-east of Bermuda (cf. p. 290), and the 

 eggs hatch out some time in the spring. The larvae or Lepto- 

 cephali, living in the upper layers of the ocean, are pro\ided 

 with curious long, needle-like teeth, which may assist them to 

 seize the minute organisms believed to form their food. They 

 at once commence the long homeward journey, the majority 

 travelling north-eastward with the Gulf Stream, floating at a 

 depth of about one hundred fathoms, in water of a temperature 

 of about 68° F. They grow rapidly during the first few months, 

 averaging about twenty-five millimetres in length in their first 

 summer, and are to be found at this time in the Western 

 Atlantic west of 50° W. Longitude. From now onwards they 

 inhabit the upper strata of the sea, sometimes being found 

 actually at the surface, and by the second summer most of 



